The Characters:

Ruki Uru Aoi Rei Kai

Dee Ivka Hitomi Natsumi Satsuri -> Nana

Sh. mama Sh. papa Sh. sis Sh. bro Sh. bro-in-law Sh. sis-in-law
T. mama T. papa T. sis T. sis T. bro-in-law T. bro-in-law
S. mama S. sis S. bro-in-law
U. mama

Hiro Yuu Ayumi Akira
Ai
Kiyone Yumi