And suddenly chanwoo just drop out of the story in the middle, like, we need closure

When they were listening to music, i believe that was the closure. Chanwoo was going to make his girlfriend happier and distance himself from Howon. "I won't become gay," he said in the forum. That meant being away from Howon so that he wouldn't end up raping him. And Howon knew that once they graduate, they'd be farther away just like when the rumors of them being gay happened.

omg i love you ty