this is a doujin so its NOT canon. but its a nice what if prequel to the main story of yoru to asa no uta which posits that the reason yakuza dude was so easy on yoru is cause he kinda has a big gay crush on him. (but since its a doujin we never see this confirmed in the main series ofc. but man...that woulda been a hot couple yo). ne way its short and funny and a quick read if u rly felt like u didnt get enough of yakuza big bro in the main story for whatever reason lol
Aru Otoko no Uta