You were born as seishu little sister, and after you grow up kokonoi and seishu got a bit overprotective about you. But only seishu know that actually kokonoi like you.. He became like this because he doesn't want you to end like akane. Sure he was rich and good at making money, but still he join that black dragon group. And he can become jealous and more overprotective since you join the toman group and get along well with mitsuya and chifuyu. He want you all by himself but scared to confess