Manga: Free Punch; Free Punch (NATSUME Isaku); フリーパンチ
Author: NATSUME Isaku
Plot: 1-2) Yamada runs away from home and goes to hang out at the school until things cool down. Unfortunately he runs into his homeroom teacher who takes him home.
3-5) Ikeda moves into his dormitory to find out his room mate Kazuma has a terrible personality.
The extra is about the first story.