I think the mangaka was trying to portray that, because he never got to fully accept his homosexuality when he realized it when he was younger, he grew up wishing to go back to the time when he was with that male classmate that he loved. Now, attacking a young boy is still a problem, but I truly think he has these feelings because he is trying to recapture his past that he missed out on. And although pedophilia is terrible, some people who know they are attracted that why want to help themselves but they can't, there are support groups for that, it is not like attraction is a choice really.
I dont think that he is a pedophile in literal way. Like, what I heard that you are considered as pedophilic if you only interested in under 12 or 9 years old children (I kinda forgot). So technically he is not a pedophile but child molester
The teacher was not a pedophile because he was not into prepubescent children; however, he was without a doubt a potential rapist.
http://www.mangago.zone/read-manga/smells_like_green_spirit/bt/323553/Vol1_Ch5/2/
I said he was a pedo because of the cover of the magazines his wife found. The first cover especially, it definitely looks like a child is posing.
I was re-reading this for the 100th time and I noticed that when his wife confronts him in flashbacks the hidden magazine she discovered actually feature what seem to be children/teenagers on the cover. I mean it was already more than implied with him trying to rape his student but it's actually 100% canon that the teacher is a pedophile. Now I wish he wasn't portrayed as a repressed homosexual, the confusion between pedo and homosexual needs to END. He might be both but his being a pedophile is absolutely condemnable and I don't appreciate the mangaka portraying him as kind of a vitim when he's done nothing to get help.