Throwing a random hc, based of a fic I read about Jigen’s mom Jigen never finished middle school (12 yo) before he started being in gang/mob (14 y.o) Also He has a perfect pitch (Oh what if he could have become a musician if he didn’t ended up in gangs and mobs)
I think I know what fanfic you're talking about! It was a pretty good one!
Now I love this whole Headcannon about him not finishing Middle School and joining the NY Mob to support his family (More specifically his mom) I swear that for a hot minute in the past I thought it was cannon, but sadly it isn't. Anyhow I've actually been thinking about what would have happened if Jigen wouldn't have become a gang member.
Would he even get to meet Lupin and the gang? Join them? Would he even know how to use a gun?
Well I still think he WOULD know how to use a gun, but for self defense. I mean, there will still be gang members around even if he didn't joined them, he would still need to protect his mother, right?
Now taking your hc about him having a good pitch and maybe becoming a musician. I like the idea of him being an opera singer or maybe a person that performs plays in the theater. (weren't does popular in that time? Not sure tbh XD)
If he even did meet Lupin it probably would be because the Genterlman thief was going to try and steal an expensive jewelry that goes with Jigen's outfit for the performance that night.
Maybe Lupin would disguise himself as another actor or a backstage staff member. One way or another he could ether steal the jewlery and leave, or somehow mess up and end up having a convo with Jigen who would simply gives him the jewlery because he doesn't care whether the rude Theater owner loses a few thousand dollars or not. Would lupin offer to join his gang? Would he simply be his friend that sends letter or comes to visit once in a while? Idk that's off to someone to figure I guess