sanemi

social life: he is also very scary like iguro and often walks around mocking people with him. he often gets into fights with people because they're picking on people he cares about (mostly his brother genya, obanai or muichiro). he beats up genya (one year below him) when he gets anything less than an A for math. he also gets into fights with his junior tanjiro because tanjiro often steps in between the fights sanemi is having with his brother's bullies or his brother without knowing what's going on. he doesn't have many friends but he is pretty close with kanae who's a year above him and sees through his tough guy act. she tutors him in biology which is his worst subject and they got close from there.

best friend: iguro, muichiro

gets annoyed by: literally everyone but especially giyuu.

love life: surprisingly he gets notes from a few secret admirers in his locker but he usually stares at them mortified and throws them away. (probably because they see how ripped he is and they like a bad boy but they're way too scared to ask him out face to face). he has a soft spot for kanae because she can see through his facade.

academic life: always gets full marks for math and is completely enraged if he gets a 99 because of a stupid careless mistake. he also gets really pissed if he doesn't get a 90 and above for physics. doesn't really care about the other subjects and gets ok marks in them (Bs and Cs). he used to get straight Cs in biology but with kanae's help he's been getting Bs instead.

favourite subjects: math and physics

before school: needs his daily dose of black coffee the get through his long day. wakes up at 6am to prepare breakfast for all his younger siblings and to work out.

after school: sanemi is in the athletic club with giyuu and the fencing club with muichiro.
he really doesn't like giyuu because he sees how good giyuu is at sprinting, long distance runs and long jump which are all sanemi's best events. giyuu also often says to the other members in the club, "i'm not like the rest of you." everyone gets annoyed when he says this, especially sanemi as they think he is saying that he's better than them. sanemi took pride in his strong body but seeing how good giyuu was at everything made him really insecure though he'd die before he would actually admit that. all his envy turned into aggression directed toward giyuu and he's really competitive with him. he is on par with giyuu and they are the best two players in the team, though none of them are team captains as one of them is too aggressive and the other is too passive.
fencing with muichiro is different because he can tell that muichiro isn't trying to be arrogant. he is clearly an airhead who is just somehow also really good at fencing. so they have a good time and sanemi really likes the challenge. he also likes gaming with muichiro on the bus on the way home because he has no other time to game.
he immediately helps his mother take care of his siblings when he gets home and works on the weekends because his family is struggling financially but he doesn't want anyone else to know. his alcoholic dad was stabbed by a stranger when he was 10, leaving him to be the man of the house. genya has tried to get a job alongside sanemi but sanemi always threatens to kill him whenever he tries. he doesn't want genya to sacrifice his childhood for the sake of his family but at the same time he takes the burden upon himself in doing so :( genya is the caretaker of the family on weekends. their mother works as a nurse so her hours are often really long. the eldest two shinazugawa brothers are often left taking care of their siblings while their mother tirelessly works night shifts. he only sees his mother late at night and always hugs her before he goes to sleep because he really loves his mom.

attire: often unbuttons the top two buttons of his shirt and teachers call him out for it but he's always sweating because he's hot and tired from working all day. walks around with a towel over his shoulder.

school bag: grey nike backpack with pen knives and army knives concealed inside...

quirk: eye twitches because of his lack of sleep a lot but it adds to aggressive personality lol