Guardians 4

Guardians 4 (ガーディアンズ 4) is a Hello! Project unit consisting of Mitsui Aika from Morning Musume, Kumai Yurina and Sugaya Risako from Berryz Koubou, and Nakajima Saki from ℃-ute. It was formed for the sake of performing music for Shugo Chara!, an anime that Buono! recorded music for. Their first two singles were used as the fifth and sixth openings for the anime Shugo Chara! Their third and fourth singles were used as the two openings to ''Shugo Chara! Party''.

Like Shugo Chara Egg!, the four members of the group wear costumes inspired by the anime. In this case the costumes are based on the school uniform of Seiyo Academy, a key location in the series. The "royal capes" are worn by the "guardians" of the school, the student council, hence "Guardians 4." Each of the members wear the same color, although the color changes with each single released.

In 2009, Nakajima Saki was announced as the leader in the making of PARTY TIME.

The final episode of ''Shugo Chara! Party'' aired March 27, 2010, effectively ending the group's activities. The group officially disbanded after performing Arigatou ~Ookiku Kansha~ with Shugo Chara Egg! and Buono!.

Members

 * Mitsui Aika (光井愛佳)
 * Kumai Yurina (熊井友理奈)
 * Nakajima Saki (中島早貴) (L)
 * Sugaya Risako (菅谷梨沙子)

Singles

 * [2009.05.27] Omakase♪Guardian (おまかせ♪ガーディアン)
 * [2009.09.02] School Days
 * [2009.11.18] PARTY TIME
 * [2010.01.20] Going On!

Complication Albums

 * [2009.12.02] Hello! Project - Petit Best 10 (プッチベスト10) (#11 Omakase Guardian)
 * [2010.03.10] Guardians 4, Shugo Chara Egg!, Buono! - Shugo Chara! Song♪Best (#2 Going On!, #4 PARTY TIME, #6 School Days, #8 Omakase♪Guardian, #13 Arigatou ~Ookiku Kansha!~ - Guardians 4, Shugo Chara Egg!, Buono!)
 * [2010.12.15] Hello! Project - Petit Best 11 (プッチベスト11) (#8 Going On!)

DVDs

 * [2010.03.17] Shugo Chara! Clip♪Best (しゅごキャラ!クリップ♪ベスト) (Guardians 4, Shugo Chara Egg!, Buono!)