a little explanation:Dazai is your sister's boyfriend but he had a crush on you, it was an act he didn't like your sister at all but what he did love is you and definitely you

You were walking down and alleyway to meet someone but this person is Hella dangerous but you liked him dazai was following you but you didn't know, you walked and bumped into this guy and he pointed a knife too your neck, dazai was following you untill he saw this and said

Dazai:HEY LEAVE HER ALONE!!!