While Tsuyoshi seems a very quiet and meek sort of guy, he has an evil side to him. Every year the same sort of thing happens. Tsuyoshi accidently calls the teacher "mother", the other kids tease him about it, and then Tsuyoshi goes on a rampage. After this initial outburst, we see that whenever Tsuyoshi gets mad he goes into a warpath of mass destruction, which can only be stopped by a karate chop by Akito directly on Tsuyoshi's head. Oddly enough he seems to have inherited this from his father...

Aya, being one of Sana's friends; is a rather quiet girl. It's revealed eventually that Aya seems to have taken an interest in a certain guy. It seems obvious with her inquisitions about Tsuyoshi, who that person is, but Sana doesn't quite get it. Unfortunately that information becomes rather... public when Aya accidently yells out that she loves Tsuyoshi in front of the entire class. Aya and Tsuyoshi get together after she sort of "exploits" his weakness for material possessions.