Tenma siblings headcanons from the top of my head
I'm a FIRMM believer that Tenma siblings are very physically affectionate (i.e. hugs, forehead kisses, cheek kisses, high fives, shoulder bumping, cuddling, hair ruffling, etc)
This takes Toya fully by surprise when they do it to him outright, without any room for denial.
Tsukasa was eating breakfast with Saki and Toya before realizing he was going to be late for a meet-up with Wondershow.
He has this thing, where he instinctively kisses Saki on the forehead before he heads off, so he does. But, in his unfiltered older brother instinct and disarray, he kisses Toya on the forehead too. And just. Leaves.
Toya kinda blue screens before snapping back and being like "what."
Saki doesn't even bat an eye lmao she just kinda looks at him like he's a little weird.
Toya: (literally saw Tsukasa kiss Saki's forehead first before beelining to him without any hesitation) "I think... he mistook me for you"
Saki: "Toya you dumb fuck (/affectionate) you've been one of us since you stepped foot in our house"
Tenma siblings cuddle a lot, usually on the couch during movies. Tsukasa in the middle, Saki to his right, and Toya to his left. They aren't aware of the set position but whenever they switch, all of them all at once just think "something is not right rn"
While cuddling, Tsukasa often uses his right hand (which Saki is leaning on) to either scroll his phone, read, or so show work (costume designing, script writing, ideas, etc). He always leans his head on Saki's. He uses his left hand to run through Toya's hair.
Toya starts referring to Saki and Tsukasa as his siblings and family outside sometimes.
Saki and Tsukasa listens to pop music sometimes. Not their main music taste, but enough for it to be significant.
This culminates to a very confusing moment for VBS, who've met Toya's biological, douche, emotionally constipated classical music family, when they hear Toya say "Oh, yeah I know Taylor Swift. My family listens to her sometimes."
Which scared VBS to their core because why is Harumichi Aoyagi listening to western white girl music
Tsukasa loves baking and cooking. It's a stress reliever thing for him. This is a huge bonus for his siblings (mainly Saki. Toya's not a huge sweets person) because there's always sweets in the pantries.
Toya never sneaks into the kitchen alone, he wouldn't dare. Plus, again, not a huge sweets person. Saki, however, is a horrible influence. They often have 2am gossip, accompanied by brownies and vanilla ice cream.
Toya and Saki can't cook for their life. (I know canonically, they're okay-ish, but hear me out.)
Toya, raised as a rich kid for most his life, has never cut a single raw ingredient in his life until his late teen years.
Saki's been hospitalized for the majority of her life.
Tsukasa's the only Tenma sibling with cooking and baking skills (considering he had to fend for himself for a while)
While they were baking together, Toya and Saki managed to get the batter on the ceiling AND explode the microwave because the batter had too much eggshells in it when they put it in. Tsukasa had to call Rui over to fix it.
Tsukasa: "I can't pay you for now, Rui I'm so sorry-"
Rui: "Don't worry about it, Tsukasa"
Tsukasa: "I'll repay you in sweets when we're done?"
Rui: "...preferably not ceiling ones but yeah I'd like that"
Ruikasa starts dating and Tsukasa swears that Rui had nothing to worry about when it comes to his family. They're welcoming! They're open! They'll love him.
Rui decided to not tell him about the glares coming from a certain pinkish blonde and split haired boy when they announced the news. (At least the parents were sweet)
Toya and Saki actually has no real gripes against Rui. They're protective, sure, they will eventually corner Rui and interrogate him, but Saki just thinks it's funny and Toya is just Toya. Rui's paranoid lmao
Akito punching Toya in the main story left a bruise (as seen in the official animation) which Tsukasa and Saki got really concerned about during their arcade hangout (Toya's first 3* side story).
Tsukasa figured out that Akito was the one who did it, and ranted to Saki about it. But he retracts it when the duo made up.
Saki isn't letting that shit go, oh no. This GINGER punched her brother?? Then, she started hearing about how Akito likes messing with Tsukasa, even insulting him to his face sometimes.
So she has a personal beef with Akito. Who didn't even know she existed.
When Akito first step foot into the Tenma household, he was dreading the presence of Tsukasa, but to his shock and horror, Tsukasa is actually more tame at home.
His biggest worry should've been the girl with pigtails, who, upon seeing him, got up from her chair and heads straight to her room. not breaking eye contact.
It takes a while, but Saki and Akito gains an unlikely alliance.
Names I gave to the Tenmas:
Tenma siblings: All three of them, at once
Tenma Twins: Saki and Toya
Tenma brothers: Tsukasa and Toya
Prototype Tenma: Tsukasa and Saki
Kohane is Wondershow's number #1 fan, probably Tsukasa's number #6 fan (I love her but her competition is Saki, Toya, and Wondershow. Idk what to tell you. At least she got a number)
She absolutely loses it when Toya got them all free tickets to one of their shows.
Akito dreads going. An is slightly excited. Kohane is radiating pure joy.
Akito nearly cries when when Kohane admits that she actually likes Tsukasa as a person, not just a performer, when she properly meets him.
Akito: "An you're my only hope. Toya's biased, Kohane's insane"
An: "idk dude Tenma and Kamishiro are pretty cool when they're not actively trying to blow the school up"
I have so much more idk maybe I'll post more later
