
Closest I can think of is When the Yakuza Falls in Love: http://www.mangago.zone/read-manga/when_the_yakuza_falls_inlove/
Romance with a frightening yakuza boss, except this ones less psychopathic and the uke babysits his son. The relationship dynamic is really similar but healthier, I actually like them more lol
Others I can think of:
Legs that won’t walk ( http://www.mangago.zone/read-manga/legs_which_cannot_walk/?kFJl)
Dangerous convenience store ( http://www.mangago.zone/read-manga/dangerous_convenience_store/)
I think Burns is also sort of similar, but the ending is hella rushed ( http://www.mangago.zone/read-manga/burns/)
Recommend pleasee