Example of open and taken characters:
Open: Inuyasha
Taken: Inuyasha

Inuyasha's group

Inuyasha
Higurashi Kagome
Shippo
Miroku
Sango

Kikyo's group

Kikyo
Kocho
Asuka

Sesshoumaru's group

Sesshoumaru
Jaken
Rin
Ah-Un

Naraku's group

Naraku
Kanna
Kagura
Goshinki
Akago
Hakudoshi
Byakuya
Moryomaru
Juromaru
Kageromaru
Muso

Wolf tribe

Kouga
Ayame
Ginta
Hakkaku

Band of Seven

Shichinitai
Bankotsu
Renkotsu
Ginkotsu
Suikotsu
Kyokotsu
Mukotsu

Modern Day characters

Kagome's mom
Kagome's grandpa
Sota
Hojo
Yuka
Eri
Ayumi
Hitomi

Other Characters

Kaede
Myoga
Totosai
Hachiemon
Kohaku
Sessoumaru's mother