Z4-B4

 is a group within Zero Project. The theme of the group is personality.

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

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

Current Members

 * Aono Kuiru (蒼乃くいる; ) (Joined November 29, 2022)
 * Usami Seina (宇参絢菜; ) (Joined November 29, 2022)
 * Jinguji Naasa (神宮司菜朝; ) (Joined November 29, 2022)
 * Fuka (柊果; ) (Joined November 29, 2022)
 * Mirahoshi Yuno (海星ゆの; ) (Joined November 29, 2022)

Former Members

 * Nanase Saaya (七瀬さあや) (Founding member)
 * Hanai Rurina (花井瑠莉奈) (Founding member)
 * Kato Rico (加藤理子) (Founding member)
 * Akimoto Maria (秋元まりあ) (Founding member)
 * Hinata Marino (日向まりの) (Founding member)