Morning Musume debuted in 1997 with five members, and has gone through many lineup and style changes through its years. They are the lead group of the idol talent agency, Hello!Project, which is made up of young female artists and groups, such as Berryz Koubou, C-ute, and Mano Erina. They are all produced by Tsunku, former vocalist of Sharan Q.
In 1997, Tsunku held an audition on the ASAYAN talent search show to choose a female rock vocalist to join Sharan Q. Heike Michiyo won the audition, but Tsunku saw greater potential in five of the remaining contestants, so he challenged them to sell 50,000 singles in 5 days. He named them Morning Musume, and they recorded the single Ai no Tane and succeeded in selling 50,000 copies on the fourth day. He gave them a record deal and the rest is history.
Morning Musume quickly became one of Japan's top groups with their fresh faces and girl-next-door personalities. The group originally started as a 5-member group, but by their second single, three more members were added. This began a series of additions and graduations which have seen members come and go, some remaining in Hello!Project as solo artists or in other units.
In April 2000, the group began hosting a television variety show called Hello! Morning (Haromoni), which further increased the group's popularity. They became a household name and were ubiquitous in Japan: they dominated the music charts, were regularly seen promoting their new singles on popular music shows, and have a lot of merchandise available, such as photobooks and DVDs.
The number of members generally remain around the 10-14 mark - the highest was 16 for a short time in 2003. Morning Musume members often participate in sub-groups and shuffle units within Hello!Project, releasing additional singles and albums.