Kento's life before the Brothel:  He lived a depressing life in servtitude to his mother that usually made him have to do some self harm to be somewhat normal. The quiet man went onto medical school since his mother determined that would make sure he earned enough money for him to support her. He did so. He ended up having a complete mental breakdown when his mother tried to kick him out but keep him paying for everything. Kento left leaving a hole in the wall.

Kento's life here:  He won't talk unless he knows you. It's due to his shut-in lifestyle from when he lived only for his mother. He's still not sure about being around people. It's not due to a bad experince just due to his mother keeping him studying or working not interacting with anyone but her. He does crave being touched ually but his social anxiety keeps him so awkward that it makes it hard to do anything with him.