Zone started off with eight members in 1997, then reduced to six and finally to four – Miyu Nagase, Mizuho Saito, Maiko Sakae, and Takayo Ookoshi – by the time they released their first indie disc in 1999.

Tadayuki Ominami, a representative of Sony Records, noticed that the crowd reaction to the group's debut concert was particularly enthusiastic. Initially, Zone was solely focused on singing and dancing. Ominami watched a live video of the band playing with instruments at the KomeKome Klub and felt that, due to the overabundance of dance groups, Zone had the makings of a breakthrough act, provided they could play their instruments as well as sing and dance.

In late 2003, Takayo Ookoshi announced her departure from Zone to pursue her studies and was replaced by Tomoka Nishimura, one of the two original members cut from the band when they scaled from six members to four.

Between 1999 and 2005, Zone released seventeen hit singles, three full-length CDs, and three DVDs, appeared in commercials, and had their own television special, in addition to attending high school. They all graduated.

Zone officially disbanded on April 1, 2005, after playing their final concert at Nippon Budokan. On April 13, their greatest hits album E: Complete A Side Singles was released. The album debuted at number 1 with first-week sales of about 98,000 copies, becoming their first number-one album on Japanese Oricon charts.[2]

Zone's music has been used in the 2003 Astro Boy series (opening theme, "True Blue" and second ending theme, "Tetsuwan Atomu: ballad version") and the Japanese release of Ice Age (theme song, "Hitoshizuku").

"Shiroi Hana" was used as the theme song to Final Fantasy Tactics Advance in Japan.

Cover versions of their song "Secret Base (Kimi ga Kureta Mono)" were used as the ending theme to the anime Kyō no Go no Ni and Ano Hi Mita Hana no Namae o Bokutachi wa Mada Shiranai.