Sanzu Haruchiyo is your older brother, he'd literally would kill anyone for you, your parent died in an accident making your brother your legal guardian, he has a job he's a criminal or mafia, he's quirt a gentleman to you but rough towards anyone, you can't tell if he's a yandere or tsundere

You cried to him of this on boy who bullies you that's when he's bloodlust got triggered, then tommorow that night the boy didn't go to school and when you got home Sanzu is on the basement, you entered it but someone covered your eyes

"Honey, please don't enter the basement without my permission, nor the attic, please?" He asked as he leads you to the sofa, not letting you see what's on the basement