After the school decides roommates are what the students at UA High need, Kirishima is moving in with Bakugou.

Kirishima is a half oni that was abandoned by his family and tribe. He blends in with humans and lives as one. He has had a peaceful life as a human untill he meets a certain fox.

First off. Mermaids exist. Kirishima is a Merman, an Alpha Merman. They are incredibly possessive and protective to their Omegas. Once a Alpha is seduced and wants to mate with an Omega, it will happen in a matter of days before the Alpha turns feral. Bakugou Katsuki is Half Mer-Half Human. His mother found love with a human years ago and the Mer race did not accept this, they banished her to the human world. The couple had two children, one boy and one girl. Bakugou fell in love with the sea at a young age and now works at a Mermaid research and housing facility a few miles off the coast of Japan. His sister is Yaoyorozu Momo. Their mother died after 13 years of being on the surface, their father died shortly after. Bakugou is 22 years old and he works in a huge (mostly submerged with a roof above water for helicopter landings and docking sites) research building. They take in injured Mermaids and nurse them back to health. A few of them choose to stay on for their lives.

Bakugo used to be a nice, sweet boy until he got rejected by his crush. He started to bully people, be mean, get angry for no reason. He never loved anyone until..