Responses
Sounds like this - http://www.mangago.zone/read-manga/kobi_no_kyoujin/
A situation, similar to what you are describing comes in ch.2.
beta
the story goes like this, a boy who used to be a drug dealer was caught stealing a customer's list. after he was beaten to pulp by the yakuza, the soon to be yakuza heir treated him for weeks to spit out where it is. i only read a couple of chapters so my memory is quite vague