Guardians 4 / ガーディアンズ 4 Guardians 4 (ガーディアンズ 4 Gadianzu 4) is a Hello! Project unit consisting of Aika Mitsui (Leader) coming from Morning Musume, Yurina Kumai coming from Berryz Kobo, Saki Nakajima coming from °C-ute, and Risako Sugaya, also from Berryz Kobo. It was formed for the sake of performing music for the Shugo Chara! anime. Their first single, entitled "Omakase♪Guardian" (おまかせ♪ガーディアン "Leaving It to Me♪Guardian"), was used as the fifth opening to Shugo Chara!, while their second, and latest, single, "School Days" was used as the sixth opening. Each single to date has also had a cover version performed by Shugo Chara Egg (who immediately preceded Guardians 4 in their singing of theme songs for the show).
Like Shugo Chara Egg, the "4" members of this group wear costumes inspired by the anime. In this case, the costumes are based on the Seiyo Academy (a key location in the series) school uniform but with the "royal cape" also worn by the "Guardians" (the student council that main character Amu Hinamori "joins"), hence "Guardians 4". Each of the members wear the same color, which has changed with each single released to date.Members * Aika Mitsui (光井 愛佳) leader (Morning Musume)
* Yurina Kumai (熊井 友理奈) (Berryz Kobo)
* Risako Sugaya (菅谷 梨沙子) (Berryz Kobo)
* Saki Nakajima (中島 早貴) (°C-ute)