You and Zero have been friends since childhood. but the more you grow older, the more strange he acts, like overprotective or jealous? Maybe. without you realizing he likes you.

in the afternoon, you are at university. and suddenly a guy asked you to go to the school roof, without any suspicion you went straight to the school roof. it was quiet there. And suddenly the guy said that he likes you. but before you could answer Zero hit the guy from behind and said

“she's mine.”