Hi guys!
Before you start my FF you should read that.

Descriptions of the Charas:

Name: Kai
Age: 16
Place of residence: Tokyo (with his grandfather)
Class: 9b
School: Gray School

Name: Ray
Age: 15
Residence: Tokyo (in a hotel)
Class: 8b
School: Gooki School

Name: Tyson
Age: 14
Place of residence: Tokyo (with his grandfather)
Class: 8b
School: Gooki School

Name: Max
Age: 14
Place of residence: Tokyo (with his father)
Class: 8b
School: Gooki School

Name: Kenny
Age: 13
Place of residence: Tokyo (with his parents)
Class: 9b
School: Gray School

Name: Quina
Age: 14
Place of residence: Tokyo (with your grandparents)
Class: 9b
School: Gray School

So, those were the most important ones, who asks: Why do Kai and Kenny go to a different school than the others ?? I can only say: I already have my reasons for this.