Azazel_'s manga / #BL(404)

A florist harasses and gets along with a 31yr old office worker. The office man likes older ppl. Mostly all his relationship have been physical and meaningless.

Two guys become best friend. There's a accident and the black haired guy disappears. The blond guy searches for him, he doesn't recognize him when he sees him. Eventually realizes later who he is. The blond and black try to find the criminal who planned the bomb of the place where the blond used to live with. Eventually they find the criminal and put him in jail. Both the friends then come together officially