I wouldn't be surprised if the hero ends up becoming the villain, and the villain the hero. I do expect the MC to face off against the Hero at some point in the story, so I think it's plausible for the hero to become antagonistic later on. A few chapters ago when he went against his father's orders and entered the school during the night he joked about how that moment might be the start of his life as a delinquent. That could be foreshadowing his life as a villain later on.
Did anyone else feel so freaking bad when he said “besides, you won’t harm me”? I wanted to cry, because I’m almost 99% sure the MC will harm him in the future