A Solid Foundation

There is no question that the lifeline of Chaldea’s operations is through the procuring of resources through Rayshifting.  Without the resources Fujimaru Ritsuka gathered to strengthen the Servants he had summoned and the quantum pieces used to operate the machines and magical equipment to do so, the entire organization’s efforts to restore humanity would have failed long ago.  So, even the most mundane of Rayshifts, the ones the young Magus subjects himself to dozens of times per day for his so-called ‘farming runs’, are treated with the utmost care.  It never failed that Ritsuka would spend hours and hours collecting the resources that Chaldea sorely lacked.

“Senpai, I believe that is enough for today.  Let’s go get something to eat.”  Helping her Master as the Coffin opened from his latest trip, the kind and responsible Shielder greeted the diligent youth.  “I’ve already asked the kitchen staff to have something ready for us.”

Taking the gentle girl’s hand as he exited the cylindrical container, looking into her lavender eye Ritsuka smiled back and nodded.  “S-Sure Mash.  Some food sounds good right about now.”

Watching the two young officers as Mash helped Ritsuka out of the Coffin, a sharply dressed man with slicked-back, black hair raised an eyebrow at the exchange.  “That is odd, I expected Mr. Fujimaru to attempt to convince Ms. Kyrielight to allow him a few more hours of Rayshifting at the very least.”

“Well that just shows you need to get out of your workshop more often, Holmes.  Fujimaru-kun has been taking better care of himself lately thanks to Mash.”  Teasing the reclusive consulting detective, the younger back-up version of Leonardo Da Vinci snickered.

“Yes, Mash really has put Fujimaru on a short leash, as it were.  Normally, letting your Servant order you around would be an embarrassment for any Master, but since Mash is a Demi-Servant… and reminds me far too much of Toole III, I suppose she’s more of an aide or assistant when not in the field.”  Chuckling boisterously, the stocky blonde man added in mild amusement.  “I suppose he has his poor pedigree to blame as well.”

“Could you really say that if Mash yelled at you, Gordy?”  Elbowing the portly man’s belly, the child-like Da Vinci giggled.  “Hmm?  Have you been sneaking snacks in the middle of the night again?”

“Wha-!?  N-No, no, perish the thought.”  Sweating a bit, Goredolf tried to back away from his Technical Advisor.

She raised her voice at Mr. Fujimaru?  Glancing back at the young Shielder as she left the room with both their Master and the fluffy, white-furred creature that so often accompanies them, the great detective raised his pipe to his lips.  How curious.

“Alright, Senpai.  Make sure you relax for the rest of the night.  No more Rayshifting until tomorrow, understood?”  Having finished their meals, Mash reminds the workaholic young man that he is to take the rest of the night off as she’s about to part ways with him for the night.  She wasn’t about to micromanage everything he did in the day, there were plenty of other Servants that wanted to interact with him in ways that didn’t involve Rayshifting.

“Right, well I’ll see you tomorrow then, Mash.”  Waving to the lilac-haired girl, Ritsuka was heading in the direction of the training room before a few of the child Servants came around the corner.

Mash giggled as the young girls jumped on the young Magus and dragged him off to play.  They ought to keep him busy for the rest of the night.  Heading back to her room, Mash rubs her lower abdomen and smiles softly.  “Gudako-senpai?  Gudako-senpai, are you awake?”

“Oh, done already, Mash?  Sounds like things are going well between you and my other.”  Replying from her favorite spot deep in Mash’s intestines, though she had been offered other locations in the Shielder’s body to rest, the redhead liked it best in her bowels.  “But you need to stop being so soft with him.  If he’s anything like me, and by the sounds of it he is just with more focus on physical training and a penis, then what you’ve done so far isn’t enough.  Just ‘eat him’ already and leave him in here for a few days.  I can guarantee that if you’re not a Servant, there is no getting out of your body without your say so, Mash, and once he gets used to it he’ll probably never want to leave.”  While her suggestion was more of a brute force solution, she knew that this world’s Mash hadn’t had her breaking point to casually disregard other people’s agency yet, so it would be a hard course of action to sell.

Shaking her head, she knew that Gudako was only concerned for her and her Master, but so directly imposing her will on Ritsuka wasn’t necessary so long as he listened to her.  “You know I can’t do that to Senpai.  Could you imagine how scared he would be if I just swallowed him out of nowhere?  Living inside of another person isn’t something that sounds healthy anyway.  Really, I’d like to let you out of there too.  Are you sure you wouldn’t prefer coming out?”

“This is a literal utopia that takes care of all my needs, why would I want to leave?”  Her reply a version of the same thing she always said, the redheaded Master for another timeline just snickered at the thought.  “If you’re worried about my health, do you know just how long of a run it is from one side of your large intestines to the other?  I’m basically running a marathon a day wading through all of your-”

“Okay, okay, you don’t have to continue!”  Always embarrassed to hear that the residents of her ‘utopia’ still had to deal with her bodily functions, it was just another reason Mash couldn’t believe Gudako enjoyed herself in her colon so much.  I would have thought somewhere like my chest would have been a better spot for her, but she insists there is less… ‘bounce’ where she is now.  Returning to her room, Mash loosens her tie and undoes the top couple buttons of her shirt as she slowly lays down on her bed.  “Okay, Gudako-senpai, can you explain it to me again?”

Mash’s Camelot

Transverse Colon

Of the six sections of Mash’s large intestines, Gudako enjoyed spending her time the most here.  Thanks to the arteries and organs close by, she could hear the gigantic Shielder’s heartbeat the clearest and the proximity to her stomach meant that, if and when this Mash finally decided to use Form Camelot on an opponent, she was most likely to be able to hear them as they digested.  While not completely sadistic, there were a few enemies that she would have liked to hear the desperate, dying pleas of, like Koyanskaya and Rasputin.

“Okay, Gudako-senpai, can you explain it to me again?”

Hearing this far too lenient Mash ask her for more advice though, she looked forward to the day when she was no longer embarrassed to use her most powerful Noble Phantasm.  Until then, she was more than happy to be of whatever assistance she could be.  “I’m not sure what more I can say.  My Mash just said ‘It’s all my body, so I can just manifest from it’.  She’d form from the surrounding flesh, either fully clothed or naked depending on her mood, and we could spend time together.  She was able to change her size as well, or maybe she was just adjusting mine, but I don’t know how she did it.”

“Hmm, I can access her memories of doing it, but it was an instinctual action.  Even though we come from the same concept…”  Concentrating as hard as she could, Mash’s face half-way formed from the intestinal wall above Gudako, though it had no distinctive features.  “I think this is the proof that we thought a bit differently.  I can’t do any better than this right now…”

“Well, it’ll probably haunt my dreams for a bit, but that is a good attempt.”  Teasing the less-confident girl, Gudako stood up and reached up to brush her hand against Mash’s half-formed cheek.  “At least I can touch you a bit like this.”

Giggling a bit, it was difficult from Mash to maintain her internal avatar as it smoothed out into the flesh she was manifesting from.  “You’re always touching me though, Senpai.”

Smirking at the light humor, the redheaded Magus spread her arms wide and embraced as much of the slimy flesh around her that she could.  “I guess you’re right.”

Laying in bed, trying to wrap her head around the concept of creating another body inside of herself, Mash just couldn’t seem to grasp what her other did so easily.  There was some fundamental principle or mindset she just didn’t share with the stricter, and if she had to be honest, more sadistic version of herself.  She didn’t exactly blame her parallel self for what she had to do to protect Gudako, but at the same time she didn’t need to manifest an avatar in her stomach to taunt and tease some of her opponents either.

However, after roughly an hour of practice, something felt… off.  Senpai?  Grabbing her datapad, Mash could see that Ritsuka was currently Rayshifting!  He’s by himself too, temporarily summoning Servants to fight.  Oh, Senpai… What did I tell you!?  Unlike the somewhat frequent times when another Servant would ask Ritsuka to Rayshift somewhere to help them out with some issue or another, this was just him out overworking himself, again.  Getting up, she marched out of her room, making a direct line to the Command Room.

Before, it used to be a bigger hassle to Rayshift to gather resources, requiring repeatedly coming back to Chaldea each time to be deployed again.  Thankfully, the process was streamlined so Ritsuka could just be sent to the same starting point again and again without coming back to Chaldea each time.  This didn’t reduce the stress on him by much, but so long as he didn’t change his destination he was able to get more work into a smaller time frame.  Even if Mash asked him not to, it was still a fact that both now and in the future, the Servants he summoned had steep resource costs to make them as powerful as he could.

If I explain myself, I’m sure Mash will understand.  Even though he listened to her when she first raised her voice to him, he had started sneaking an extra hour or so of resource gathering when she was preoccupied with something else.  Finishing up for the day, he was ready to return to Chaldea and go back to his room before she found out.  However, as his Coffin opened up, the stern face of the Demi-Servant’s one revealed eye stared at him with no intention of humoring excuses.  Well, crap.

“Senpai.”  Grabbing his arm, Mash dragged him out of the Command Room, with the staff averting their eyes and DA Vinci-chan giggling at the young Master.

He didn’t need to hear the young looking Caster’s ‘I told you so’, since she had tried to advise against him going against Mash’s orders.  “L-Look.  Mash, I know you’re upset, but we only found out about Comet Shards recently and we already don’t have enough, not to mention all the Eggs we still need.”  Trying to justify his actions, he wasn’t able to slip from her grip as he was led back to his room, not unlike a child about to be punished by their parent or guardian.  “C’mon Mash, can’t we talk about this?”

“No, Senpai, I do understand.”  Not looking back, Mash replied to the young man’s concerns.  “I know you’re just trying to be the best Master for all the Servants you have summoned that you can be.  You want them to be at their strongest to reduce the chances of them getting hurt in combat so you push yourself to gather the resources they need.  I understand what you’re doing and why you’re doing it.”

“Then why are you stopping me?  Just a couple more hours a day can’t hu-”

“Not today, but it will!”  Despite still being in the halls as they approached his room, Mash didn’t keep her voice low.  She couldn’t.  Not when images of Gudako’s breakdown, crying in anguish on the floor flashed through her mind.  It was an admirable quality to push oneself for the betterment of others, but not to the point of self-destruction.  Slowly but surely, day by day, the stress will continue to increase, and while he might be able to handle the pressure now, he isn't recovering enough to sustain his workload.  “You’re thinking too much of everyone else, but what about you?  You can’t disregard your own health to help others like this.  Eight hours was a normal work day in modern society, so I thought it was a fair compromise to allow that, but apparently I was wrong.”  It wasn’t just today either. Because she trusted her Master, she hadn’t been checking his Rayshifting logs, but it seemed like he had been going behind her back for a while now and lying about it.  On this issue, at the very least, trusting him was a mistake.

“Mash, it’s fine.  I’m fine.  I need to do what I can to make up for my deficiencies as a Master, fighting the Crypters has shown me just how far below the bar I really am.”

Oh, Senpai…  While there was some truth to his self-disparaging comment, it was unlikely that it was a sentiment shared by any of the hundreds of Servants contracted to the young man.  Mash especially didn’t see him as inferior to her old teammates.  However, her Master’s perception of his self-image and overworking his body were two separate issues right now.  “Fine, I’ll let you Rayshift more than eight hours a day, Senpai, but only on one condition.”  Dragging him into his room, Mash decided to re-compromise.

There was something about the confidence that his kouhai was emanating that unnerved Ritsuka, like posing her condition as if he had a choice was merely a courtesy.  “Alright Mash.  What’s your condition?”

“Don’t worry, it’s nothing too difficult to fulfill.  For every hour of Rayshifting you wish to go over, you just have to do 25 push ups with me watching.  But you have to do a full 25, Senpai.  If you quit at 24, that won’t count.”

It seemed like an easy enough condition to meet, and since it was coming from someone as honest and earnest as Mash, there was no need to think about it too deeply.  She wouldn’t back out of her word, even if he did 100 push ups right now.  “Deal.  So, can I try to get some extra time now?”  Unbuttoning his shirt, Ritsuka tossed it onto his bed and stretched his arms a bit.

“Of course.”

Getting down on the floor, hand’s shoulder width apart and legs straight, Ritsuka shifted his weight on his hands to get comfortable, but before he could start, something soft and warm pressed down on his back and he was forced to restabilize himself as some extra weight settled on top of him.  Looking back, he saw the concerned Demi-Servant wiggle her butt into his back to get comfortable as she brushed her hair aside and looked back at him.

“Hmm?  Is something wrong, Senpai?”  She asked with the innocence that only she could.  “I never said that I wouldn’t make it more difficult, and you didn’t say I couldn’t, right?”

“Um, n-no…  No, I guess we didn’t.”  Staring back at the floor, blushing intensely, rather than the bit of deception he would have expected from an Evil-aligned Servant, like one of the oni or pirates, all Ritsuka could think about was the plump backside pressing down on his muscles.

Likewise though, Mash immediately began to regret her decision as soon as she saw the look on his face.  Th-Th-This is really inappropriate, isn’t it.  M-Maybe I should stop before-

“That’s it Mash!  Don’t give up now.”  Encouraging her from her utopia, Gudako’s voice rang in the Shielder’s mind.  “You need to commit, don’t let him see any weakness!”

“Gudako-senpai?”  Her doubt wasn’t entirely cleared, but just thinking of the redhead and the suffering she had to endure was enough for Mash to steel her resolve.  That’s right, in order to keep Senpai from suffering like her, I can’t be like I used to be.  My other self, help me please.  Grinding her rear into the young man’s back a bit more before slipping her feet out of her heels and resting them on his legs, she looked back at her Master and giggled a bit.  “Are you not going to start, Senpai?  Your back is quite comfortable, so I don’t mind sitting here for a while.”

Caught off guard by the borderline domineering comment, Ritsuka snapped his attention back at the usually timid and reserved girl’s forwardness.  However, the look in her eye, which looked to be blooming back into its captivating lavender from a pale amber, gently intimidated him into silence.  He had seen her toss Phantasmal Beasts and even armored vehicles around on the battlefield.  At least she isn’t pushing down on my back.  Bending his arms, he lowered himself until his elbows formed 90 degree angles and as had been drilled into him by some of the best instructors human history had to offer, he held his form for a second before straightening them again.  “One.”  Confident from the ease of the first push up, he grinned back at the Shielder girl.  Mash is lighter than I thought, this shouldn’t be too hard.

While she was expecting him to be able to handle her weight rather easily, Mash was still impressed as Ritsuka continued at a steady pace.  Seeing his biceps and triceps bulge as he lowered his body and feeling the muscles in his back flex under her rear, she could sit and watch him exercise for hours without getting bored.  However, his pace continuing unaffected as he reached the double digits, she began to get a bit nervous.  Did I underestimate Senpai’s fitness?  But, if he gets to 25…

“Thirteen.  Fourteen.”  While he had to admit that having someone sitting on his back was making things a bit more difficult, the young Magus was sure he could clear Mash’s condition easily, though 50 might be pushing it a bit.  But if it gets me another hour, I’ve got to try.  “Fif-teeeeeeen!”  Pushing himself up to complete another rep, suddenly more weight bared down on him, catching him off guard and almost buckling his arms.  Thankfully he had the proper form to distribute the load properly, so as he straightened his arms, wondering what happened, he looked back to see what was increasing his burden.

Half expecting to see one of the more mischievous Servants having seen Mash sitting on his back and decided to join her, he was surprised to see that the earnest Demi-Servant had instead decided to manifest her combat suit and armor!  Unlike the armor she had when Galahad was supporting her, the Ortenaus armor she had been using since they started clearing Lostbelts was bulkier and thicker, making at all the more heavy, especially her grieves and boots.  It was as if another Mash was now sitting on his back!

Oh, that’s gotta be cheatin-

“Hmm?  Is something wrong, Senpai?”  Noticing his pace had stopped, and with the most innocent expression despite knowing what she was doing, Mash acted like nothing was wrong.  “We agreed that you only have to do 25 push ups, didn’t we?  Why have you stopped?  Are you tired already?  I keep telling you you’re pushing yourself too much.”

It was a devious move that he wouldn’t have thought she would pull, though it also wasn’t entirely out of character for her to go above and beyond for his sake.  Well… 50 is out of the question, but I can still get another hour if I push it.

Watching her Master continue undeterred by her… increasing the difficulty of his task, Mash’s admiration for him only deepened.  Wow, I thought Senpai would give up after I manifested my armor.  She should have known this level of adversity wouldn’t be enough to stop him.  Though him getting up to 20 was making her increasingly worried.  I’m sorry, Senpai!

Just 5 more.  Just 5 more and then I’m done.  Sweating and breathing heavily, Ritsuka took a moment to focus.  His arms were burning and trembling, but he knew he still had the energy to finish the set.  Or, at least he believed that to be the case until the burden on his back increased once more as he was eclipsed in a large shadow.  Just barely able to catch himself as his face and chest were almost forced to the floor, he pooled as much strength into his arms as he could to push himself up for his twenty-first push up before turning his head to see what Mash had done.  No way!

He didn’t have to turn his head far in order to see one of the stubbier arms sticking out from the side of her large,cross-shaped, round shield.  Just like the armor developed after Galahad’s departure, Lord Camelot’s degraded form was much bulkier and heavier in an attempt to restore a semblance of its former functions and durability.

Laying down on Ritsuka’s broad back, Mash didn’t address manifesting her class’ namesake at all.  She needed to ensure he rested properly, no matter the method.  “But this feels a bit mean, don’t you think Gudako-senpai?”

“If you’re not going to nom him, you need to make him realize that going against your orders is a bad idea, Mash.  By all means, bring him into your body if you feel like making him sweat under you is too much, but you have to admit you’re enjoying yourself.”  Not allowing the still far too lenient girl to backstep, the redhead playfully teased her bit to get her mind off of it.  “The smell of his sweat, the heat radiating up through your back, his firm muscles supporting your body.  Just think about it, Mash.  As long as he’s under you, he’s safe.  Just keep him there, make him stay by your side and you can protect him.”

Her heart fluttering at the idea, the Demi-Servant turned her head slightly so she could see the determined, strained expression on his handsome face.  His grunts and groans as he lowered himself and pushed with all his strength just to squeeze out another repetition.  And maybe it was a side-effect of gaining the other Mash’s Noble Phantasm… but he did smell delicious.  Licking her lips, she recited the incarnation in her head.  True Name… clarion summon!  May purity cleanse the wicked and this temple shelter the wounded…  Come to me…  Opening her mouth just a crack, if she had the reserves of Mana right now, her Master would be experiencing a force pulling on his body, pulling him towards her lips.  In an instant, he’d be whisked away and compacted down until he fit in her mouth where she could deposit him wherever in her body she wished.  Then he’d never go behind my back again, Senpai would be trapped inside of me, forced to let his body rest for a change.  It was tempting and far too enticing since she could easily go borrow a Kaleidoscope.

“Besides, you got excited when you sat on him.  Don’t try to deny it, I heard your heart rate increase.”  Not privy to the thoughts running through her caretaker’s head, Gudako continued to push for Mash to take more tangible actions.  “Make him submit and you can do more than just plant your cute, plump tush on his back.”

Gudako’s ‘advice’ invoking an image of her sitting on her Master’s lap, pinning him to a chair with nowhere to run, Mash’s train of thought was completely derailed by embarrassment!  “Gudoko-senpai!  This is for Senpai’s benefit, not mine!”  What she was doing was something she’d expect Stheno or Euryale to do, and when she thought about it like that, she couldn’t believe how inappropriate she was allowing herself to behave!

“Twenty…”  His arms visibly shaking as he squeezed out the last bit of his strength and unaware of the dialogue going on atop him, Ritsuka pushed himself up one last time as sweat ran down his brow.  “...five!”  No sooner did he finish, though, did his arms give out from under him.  Pushed beyond their limits, they couldn’t sustain the weight resting on them a second longer.  But, instead of the cold, hard ground rushing to meet him, the Japanese boy felt himself get held aloft as a slender arm wrapped around his chest from behind him and two large, soft masses pressed against his back.

Demanifesting her shield and armor when she felt her Master begin to collapse, Mash was able to catch him by quickly turning over and planting a hand on the floor, using the other to hold him against her.  His shirt quickly soaked through with his sweat and she could feel his heart racing to supply his body with the oxygen it so desperately needed.  Standing up, she smiled at him.  “Good work, Senpai.  That’s 25.”

“Yeah, it was a bit more difficult than I thought, but once I catch my breath I can-”

“So that covers the extra hour you’ve already used today.”  Continuing to smile sweetly, she manifested her armor and shield again.  “Would you like to try for another 25, or would you like to rest now?”

Dumbfounded, Ritsuka could do nothing but stare at the sweet girl in disbelief.  She had no intention of letting him continue to Rayshift for the day and he fell for her trap hook, line and sinker.  Between normal Rayshifting and sleeping, I don’t think I could try for extra time more than once a day either.  I guess I really upset Mash this time.  Realizing his mistake, Ritsuka just fell back onto his bed and chuckled a bit.  “No, you win Mash.  No more farming for me today.”

Looming over him, Mash giggled back.  “That’s good to hear, Senpai.  Starting tomorrow you can start to make up for the other days you snuck out behind my back, ten hours in total by my count.  If I catch you trying to sneak off before you make that up to me, or in the future, I’ll have to take more… drastic measures.  Okay?”

Even though she was smiling, her tone impressed how serious she was on him and Ritsuka got a chill down his spine.  This wasn’t drastic?  Recalling the heft of her weight on his back, especially the feeling of her soft rear when she planted it on his back, Ritsuka couldn’t fathom what she could do that would be more extreme than that.  “Alright, alright…  S-Sorry Mash.”

“As long as you understand and start taking better care of yourself.  I just don’t want to see you hurt yourself, Senpai.”  Standing up and turning to leave, he was too exhausted to do much else and at least for tonight he wouldn’t try to go behind her back to do anything else.  “I’ll see you in the morning.”

“Yeah.  Good night.”  Watching as she left the room, Ritsuka’s eyes were drawn to the round curves of her butt and how much the form-fitting bodysuit of her Servant outfit complemented her figure as she shifted her clothes back to her Chaldea uniform.

Bowing as she exited his room, Mash stopped herself from running back to her room in embarrassment from how brazen she realized she had acted.  I sat on Senpai.  I sat on Senpai.  I sat on Senpai…  and I wanted to sit on him before I left!  Seeing him so helpless on his bed, she was tempted.  If she had climbed onto his bed and planted her butt on his chest as she warned him to not repeat his dishonest actions, she was sure the message would have gotten across.  “Gudako-senpai!  What are you making me think!”

“Hmm, if I had to guess, complete and total domination of my other, right?  What do you want to do to him?  My Mash had to hold me down and-”

“I couldn’t do that to Senpai!”  While often convenient, getting flashes of her other self’s memories when the tiny redhead mentioned something wasn’t without its disadvantages.  Because the more confident version of herself didn’t hold back, it didn’t take long after she stopped allowing Gudako to hurt herself that they became intimate with each other.  “I know I did it for his own good… but what I did to Senpai was out of line… and a bit mean…”

“But you got a bit wet seeing him struggle under you, right?”  Unashamed and actively hoping that Mash would stop holding back her feelings, Gudako kept pushing her to come out of her shell.

Blushing all the way to her ears, Mash didn’t want to think about the itch in her sex or the dampness of her underwear.  Even when she first sat on Ritsuka’s back she was trying to deny how much she enjoyed it.  But the more Gudako pressed her on the matter, the more she had to face her repressed feelings.  She always admired watching him workout and exercise, usually from afar or just the sidelines.  She got a massive boost to her physical and magical parameters when she became a Demi-Servant, but her Master continued to try and improve himself how he could and offered to help at every opportunity.  However, it wasn’t watching him push himself that she enjoyed the most, but seeing him spent, on the ground after wringing out every last drop of energy he had.  And now that she got an up close and personal view of him as he worked himself to exhaustion, she knew she wouldn’t be satisfied with just watching from afar anymore.  “Y-yeah…  He looked so handsome, struggling under me like that.”