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

 * Aimi Yuka (藍南ゆか) (Joined March 6, 2023)
 * Kayano (かやの) (Joined March 6, 2023)
 * Todoroki Shizuku (轟雫玖) (Joined March 6, 2023)
 * Hikari (ひかり) (Joined March 6, 2023)
 * Musubi Meru (結める) (Joined March 6, 2023)

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)
 * Aono Kuiru (蒼乃くいる; ) (Joined November 29, 2022)
 * Jinguji Naasa (神宮司菜朝; ) (Joined November 29, 2022)
 * Mihoshi Yuno (海星ゆの; ) (Joined November 29, 2022)
 * Aisaka Yuuna (逢坂ゆうな; ) (Joined December 28, 2022)
 * Fuka (柊果; ) (Joined November 29, 2022)
 * Usami Seina (宇参絢菜; ) (Joined November 29, 2022)
 * Yugi Hirune (柚木ひるね) (Joined December 28, 2022)
 * Gifuto (ギフト) (Joined December 28, 2022)
 * Rio (りお; ) (Joined December 28, 2022)
 * Miyamori Nozomi (宮森のぞみ; ) (Joined December 28, 2022)
 * Shigeta Norika (重田紀香; ) (Joined December 28, 2022)
 * Himekami Ranno (姫上ランノ; (Joined December 28, 2022)