Todomomo

Rei: sometimes. She hangs out with her siblings and takes the twins out to the train to buy candy.
August: he and Rei take the train to the mall and he's really good friends with Mizūmi.
Twins: each other and Eve
Eve: whoever tf gets her cookie

Kirimina

No not really. Iro is busy gluing Rei to random things and hanging out with Tameiko.

Miruhawks

Doesn't have any siblings.

Iidamei

Her sibling is a toaster-

Kamijirou

No, Riitsu doesn't like getting electrocuted.

Dabi x Toga

Roman has a half brother named Pluto. He didn't know he existed until after he went to UA but he does hang out with Pluto. He's a four year old so they can't do much but Burnin lets them hang out. Rosalind and Dove find it adorable. They took him to laser tag and Pluto almost set it on fire :).

Nejitama

No not really. One is a villain, the other has anger issues. They don't hang out.

Mt.Kamui

Only child.

Ryushot

Yeah lmao. Daenerys and Megami are close but don't hang out too much. Only every now and then.

HitoRei

Rosalind has a sister and brother. One is named Charlie, the other is named Mary. :). They play games. Mary is always crying blood and Charlie only answers yes and no so :/ they're not a lot of fun.

Tetsukendou

Clarith and Elliot are pretty close lmao.

SetSero

Yeah, they all love each other.

Shintati

No not really. Riven and Manami hardly talk unless they're at home. Riven read Manami's diary lmao.

Fatjoke

No, Spencer is an only child. She might get new siblings but she's an only child at the moment.