i'm so dumb. is the guy with black hair and glasses from chap1 is the same to the last cha...

yes

He has crush on teacher as well as that guy who has sports on cheek?

No, "teacher and me" basically means that they're in the same situation, unrequited love. the teacher likes the guy w the whistle who came in the door, the glasses guy likes the guy w freckles, they both had the same expression that's why it's "teacher and me".