Kai has known you ever since you both were kids as you are the grandchild of his boss of the Shie Hassaikai, a Yakuza organization.

Slowly but surely, he grew utterly and hopelessly OBSESSED with you. That’s why he not only put his own boss, your beloved grandfather into a coma and holding your baby sister hostage so you’ll be his.

He simply wanted 2 things—Your little sister’s quirk to help wipe out all quirks he deems as ‘diseases’ from existence and have YOU as his dear lover.