°C-ute was formed in June 2005 with 7 members: Umeda Erika, Yajima Maimi, Nakajima Saki, Suzuki Airi, Murakami Megumi, Okai Chisato and Hagiwara Mai. Originally these members were supposed to take part in Berryz Koubou, a Hello! Project Kids group that intended to periodically rotate its members, but it was decided in 2004 that the original members of Berryz Koubou would be permanent. A year later, °C-ute was formed of the remaining Hello! Project Kids members.

The group was officially announced on June 11, 2005, though its formation had been rumored for several months prior. Prior to the band's formation, some members worked with members of Morning Musume in such side projects as Aa! and ZYX, as well as the Mini Moni movie Okashina Daibōken

In January 2006, Arihara Kanna, originally a Hello! Pro Egg, was added to the group and was introduced during the Hello! Project 2006 Winter Concert Tour. Four months after the newest member was added to the group °C-ute debuted in the indie scene with their first indie single titled Massara Blue Jeans.

On October 31, 2006, Murakami Megumi suddenly announced her graduation from the group and from Hello! Project, without a graduation ceremony. Although the official reason was so that she could concentrate on her studies, many fans believe she left because she had been photographed walking together with a guy just a few days prior to the announcement.

Seven months after the retirement of Murakami Megumi °C-ute was signed to zetima, being label-mates of Morning Musume they debuted in the major-music scene with their single Sakura Chirari and ranked in the Top 5 on Oricon Chart.On the first day it ranked third on the Oricon charts, a feat not even accomplished by Morning Musume (who had ranked 6th on their debut single). With their debut single, they became the youngest group (with the average age of 13) to rank in the top 5.

°C-ute had a weekly thirty minute radio show called "Cutie Party". It began on October 7, 2006 and aired on FM FUJI every Saturday from 23:00 to 23:30 as the opening portion of Hello! Project Night. In 2008, it was replaced with Cutie☆Paradise. Like Morning Musume before them, at their debut concert each of the group's members were given a color used for merchandise, costumes, and the like. Those colors: Umeda Erika - yellow; Yajima Maimi - pink; Nakajima Saki - orange; Suzuki Airi - green; Okai Chisato - blue; Hagiwara Mai - purple; and Arihara Kanna - red.

On late 2007 the single Tokaikko Junjou was released, this single became their best-selling single to date with over 38,000 copies sold.

In the fall of 2007, °C-ute entered into the spotlight in the Japanese media because of their rising popularity, increasing sales and award nominations. °C-ute was a nominee for the "Newcomer Award" as part of the annual YTV show "Best Hits Kayousai". Although they didn't win, they got a prize for being the runner-up and performed on the show.

On November 26th, it was announced that they were nomined for the 40th Japan Request Awards, a radio-related award (presented to artists who gets the most number of their songs requested). They didn't win, but they got medals for being the runner-up, and performed on the show. On November 29th, it was announced that °C-ute had won the New Artist Award from the 49th Japan Record Awards (Nihon Record Taishou), along with JYONGRI, Stephanie and Takasugi Satomi.

On December 30, 2007, °C-ute was chosen as "Best New Artist" by Japan Record Awards, 14 out of the 21 panel judges voted for them. Producer Tsunku received the award while the screen showed the girls crying at the dressing rooms after their performance.

In December 2007, °C-ute (along with Morning Musume and Berryz Koubou) performed at the 58th Kouhaku Uta Gassen.

In early 2009, Arihara Kanna, temporarily left the group and was expected to have surgery to correct a bunion. She was expected to later rejoin the group. However, she graduated on July 9, 2009, from the group and from Hello! Project, without a graduation ceremony. There have been rumours about her being seen with a boy, which was against her contract, and many of her fans believe that this could have been another reason for her sudden departure.

A month after Arihara Kanna left °C-ute, it was announced that another member will be leaving too. Umeda Erika graduated from °C-ute and H!P on October 25th, the last date of their concert tour, in order to pursue a model career. This is the third member to leave the group but the first to have a graduation ceremony.

EVERYDAY Zekkouchou!, released on September, was Erika's last single in ºC-ute. The single ranked #2 weekly and topped the daily charts with a #1 position in its first week, this is the first time for the group to reach #1 daily and currently ºC-ute's highest-charting single overall.

At their First Event as a 5-nin Group each of the members were given a new color used for merchandise, costumes, and the like. Those colors are now: Yajima Maimi - red; Nakajima Saki - blue; Suzuki Airi - pink; Okai Chisato - green; Hagiwara Mai - yellow.

C-ute announced on a live radio show that they would be opening up a blog. SHOCK!, ºC-ute's eleventh major single, was released on January 6, 2010. It topped at #1 for the daily charts and #5 for the week, selling 18,665 copies. This is the first a-side of a single to have all solo lines given to only one person (Airi) with the rest of the group singing only the chorus as well as their first single as a 5-nin Group. read more