Shou met several people bullying a little boy at the entrance of an alley on his way home. He chose to ignore it and was later bullied.
He chose to ignore it because he also experienced this in his childhood and he didn't want to experience it again.
And Gong is just a bystander from beginning to end. He has a long background, is easy to learn, and is excellent. He has never paid attention to Shou.
Gong finally found out that Shou was killed because of his assailant. The school told the incident in the lecture hall with the theme of school violence.
Mission: I wish there would be no school violence in the world