tsf 1

i’ve been thinking of that cute comic you linked to me where shinji’s body was slowly feminizing itself and i kinda got carried away and thought up my own story based around that happening. because tsf is great and i haven’t explored a slow burn tsf enough at all!!

while it isn’t likely that byakuya knows anything about zouken’s true intentions with the holy grail war and procuring an heir, he has enough traumatic memories from his youth and his failures as a mage. he’s been into the basement and he knows that fear. he eventually admits to his expecting wife the horrors of the matou family magecraft. or, at least, what he knows of it. he knows that if their child has healthy circuits they’ll be forced into it and byakuya apologizes for being too cowardly to be able to go against zouken otherwise.

i like to imagine shinji’s mother as someone practical and seemingly traditional that people maybe don’t expect much from, but she’s actually very sharp and even playful, and tries to smile often. even if it was an arranged marriage, she was a good match for byakuya, who struggled with confidence and relied on negativity.

it would be really neat if her family’s trade was small potions of the genetic altering kind. usually nothing too major, typically cosmetic: changing eye color; removing freckles; maybe even growing back a missing finger that was lost. they were seen as third rate in comparison to the rest of the magus world as they didn’t meddle in anything too extravagant and thus were seen as underachievers by some.

but maybe, to soothe the worries of herself and her husband, she developed something to take during her pregnancy to ensure their child would be born male. it was her line of thinking that if her baby had healthy circuits and was made to be an heir of the matou family, a son would have the strength for a fighting chance and byakuya would smile a little more. she worked diligently and in secret to create a potion for herself and months later proved to be successful. their son shinji was born and for a few weeks she and byakuya were so genuinely happy to be together as a family that neither of them expected any backlash when shinji’s magic circuits were in shambles — much worse than byakuya’s. despite pained offers that they could “try again” (all the while visibly protective of their son) zouken killed her. byakuya died then too, though his body didn’t follow for many years.

it’s not until shinji’s last year in high school that the protective charm his mother left inside his body starts to lose its effect. at first he thinks it’s just a summer cold — his limbs ache and he feels consistently queasy. sakura expresses her concerns to shirou, who subtly begins to look after him by offering homecooked pieces of his lunch. when he points it out to shinji that it looks as if his uniform isn’t fitting properly these days, he’s answered with an outburst and text messages consistently left on read.

the physical changes to his body were slow and subtle. so slow, even, that shinji was so distracted by how ill he felt that he didn’t notice how much softer his skin felt. he didn’t notice how his hands, wrists and feet looked more delicate, or the slight curve to his hips. it wasn’t until, during a balmy september evening that he woke up gasping and feverish with his clothing sticking to him that he really was becoming a different person. pulling up his shirt and cupping his chest, he knows he can’t pretend Nothing Is Happening anymore. his breasts start out small. they don’t grow quickly. they’re less than a handful until christmas. shinji wraps his chest diligently every day, wearing it as tight as he can for as long as he can.

he tries to act the same at school and around friends, though he often ends up nervously overcompensating with bravado. he still tries to avoid shirou, if only because he Really Really Likes Him and all of this weird junk happening to him is not conducive to trying to pursue him romantically.

but it’s stressful and he’s shinji, so he acts like a dick about it.

he avoids sakura quite a bit at home, too, but she takes note of small things she finds strange about him. his sudden, persistent back pain and subtle curves just being the beginning of it. shinji often takes meals in his room and then studies until early morning hours. at kyudou he becomes increasingly frustrated with his abilities not just because he can slowly feel a shift in his upper body strength, but because pulling back brushes against his chest and he becomes self-conscious.

the winter is welcome because it allows shinji to hide in bulkier clothing and wear boots with lifts to make up for his now decreasing height. he’s becoming more frustrated with his research, however, because he’s got no leads. he goes to rin tohsaka to confide in her and ask for her help, but chickens out at the last second. it leaves her suspicious and concerned.

immediately after, shinji shows up at shirou’s house. he walks in wordlessly and judging by how defeated and sullen he seems, shirou only thinks to prepare some tea and let him take whatever time he needs. a few hours turns into overnight and overnight turns into a few days. it becomes obvious that shinji was lonely, so shirou doesn’t mind keeping him company even with minimal conversation. shinji’s voice seems softer, but it still has the same amount of bite.

eventually, even knowing the risk of asking, shirou asks if shinji is sick.

shinji says he doesn’t know, but maybe.

it’s the first time shinji has ever admitted to shirou he didn’t know something. so he asks him to stay as long as he would like.