Z4-B5

 is a group within Zero Project. The theme of the group is K-Pop.

The first line-up was announced on November 20, 2021.

They made their stage debut on November 21, 2021 @Ebisu Garden Hall.

Current Members

 * Okiku (おきく) (Joined March 6, 2023)
 * Natsuna Rika (夏菜莉歌) (Joined March 6, 2023)
 * Watanabe Runa (渡辺瑠菜) (Joined March 6, 2023)

Former Members

 * Megu. (メグ) (Founding member)
 * Azuki Miyu (愛月心結) (Founding member)
 * Alyssa (アリサ) (Founding member)
 * Tsuno Hirona (津野紘菜) (Founding member)
 * Nanase Ren (七瀬澪) (Founding member)
 * Rukino (るきの) (Joined March 6, 2023)