566

566 is a five-member music unit that made its debut in 2000 together with Nakano Sayuri as 566 featuring Nakano Sayuri, providing Never Say Why, Never Say No, the seventh opening for hit television anime series Kindaichi Shounen no Jikenbo.

They haven't released any other singles thereafter and have only participated in lives and as support for other acts, including TM NETWORK.

(Source: AniDB)