maybe the teacher guy told the rest of the guys what happened in the bathroom that one time so they are all awkward when they talk to him? That's just my guess though
No, it's because the Japanese have a stricter sense of personal space than the mc, they're probably not used to another dude grabbing their hand etc.
Wait... Is the Mc not a Japanese? Is he a Korean? Since Koreans are usually okay with skinship
The mc is Korean but everyone else is Japanese
Is everyone in that Yakuza household secretly whip for the uke? (≧∀≦) he said everyone blushes when he touches them so uhm...