The teacher like her older sister so he is not pedo lol(づ￣ ³￣)づ
He was trying to get into her good graces so he could get information about her sister. It is quite common for people to do that. They mean no harm and to be fair, it is the quickest way to get close to the actual person they like. Unfortunately, him buttering her up gave her the wrong impression. (Not exactly helped by her classmate!) So he isn't a pedo. Just a shy guy who wants to get to know a beautiful woman he saw with one of his students.
What is pedo in your mind? He teachs high school students, not elementary kids. Is an age gap consider pedo?
Well, giving that the high schoolers are still minors and he is an adult, that would be considered pedophilia if it was anything other than teacher and student in school
Semi hot teacher: Hey y/n how would you feel if I rounded your grade?
You: (notice he didn't ask anyone else and begin thinking how he is kinda cute and nobody loves you so it might be worth
Senior hot teacher: Say what ill boost it two percent?
You: (thinking how you need that extra percent to pass the class and begin thinking of your future together) well for what?
Semi hot teacher: well I wanted to ask if you could talk to your sis-
You: (you could hear your heart break to pieces and anything he says is just blurr, your imagination of your future with him collapses
You: (saltily) sure whatever
Sorry this is not a Japanese manga. Koreans don’t fuck with that.
The teacher seems a little iffy to me. Probably a pedo lol