Z4-B1

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

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

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

Current Members

 * Suga Koharu (須賀小陽; ) (Joined August 2023)
 * Tsubaki Karen (椿かれん; ) (Joined August 2023)
 * Shizuku Hana (雫羽菜; ) (Joined August 2023)
 * Hashimoto Akane (橋本あかね; ) (Joined May 24, 2023)
 * Natsuno Suzuka (夏乃すずか; ) (Joined August 2023)

Former Members

 * Shukuzu Nuko (酒屑ぬこ) (Founding member; Graduated February 28, 2022)
 * Tsukino Mizuki (月野みずき) (Founding member)
 * Asahina Rin (朝比奈凛) (Founding member)
 * Ueda Moca (上田望夏) (Founding member)
 * Yuzuki Misato (雪月みさと) (Founding member)
 * Misora Rin (海空凜; ) (Joined November 29, 2022)
 * Miyata Yume (宮田有萌) (Joined November 29, 2022)
 * Tadano Honyon (只野ほにょん) (Joined November 29, 2022)
 * Tsushiro Mai (蕾白苺; ) (Joined November 29, 2022)
 * Rinka (凛華; ) (Joined November 29, 2022)
 * Ayase Mayo (絢瀬まよ; ) (Joined December 28, 2022)
 * Isshiki Hiyori (一色陽頼; ) (Joined December 28, 2022)
 * Hanamaru Yuzu (花円柚羽; ) (Joined December 28, 2022)
 * Yoi (宵; ) (Joined December 28, 2022)
 * Ogawa Urara (小河うらら) (Joined March 6, 2023)
 * Ato Rie (あとりえ) (Joined March 6, 2023)
 * Amamiya Mizuki (雨宮美月) (Joined March 6, 2023)
 * Inoue Sakura (井上咲愛) (Joined March 6, 2023)
 * Tsukishima Mimika (月島美々花) (Joined March 6, 2023)
 * Kamino Saya (神乃さや) (Joined May 24, 2023)
 * Kurokawa Nao (黒川奈音) (Joined May 24, 2023)
 * Amane Hana (天音巴七) (Joined July 2023)
 * Kouzuki Hana (香月はな) (Joined July 2023)
 * Sakurazaka Ai (桜坂愛衣) (Joined May 24, 2023)
 * Yukishiro Rina (雪白璃奈) (Joined July 2023)