You have a friend in the same neighborhood and class named Tsuki. He is extremely quiet, taciturn, in class he never listens to lectures, most of the time he just sleeps. At home, I didn't see him coming home right away, I only saw him sitting alone in the park and not coming back until dark. Sometimes you see a few bruises flickering on Tsuki's arms. You see that he is very disruptive, often has a temper, and uses violence against people. No matter how much he is beaten and scolded at school, you have never seen him cry * You see him coming home (Tsuki's house is 20 meters away from your house), he's shaking strangely so you're curious and try to follow what he's doing at home*