who that guy?

It's the geography teacher who seems to have some kind of relationship or interest in Kwon. Or vice versa.

Uh when was that? What chapter? Omggg

He was the one who got Moog to get Yohan to sign the volunteer slip for the group project. He pops up a few times usually to talk to Kwon or is approached by Kwon. They're quite playful with eachother but they have an interesting scene next chapter that is about the most interaction i've seen them get but i have no idea what the context is.

Wahhhh so it's possible Yuri would also have his love story thanks btw!

Relationship with a teacher? Isn't that all kinds of creepy, and illegal...

I said some kind of relationship. That could include family or friends, relationships aren't all automatically romantic, yeah. Since they're friendly I wondered if they knew eachother prior to him (the teacher) coming to the school since he's new but really, I don't know the context of ch 27. He and Yuri probably just enjoy eachothers company in a platonic way.