Z5-B1

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

The first line-up was announced on July 9, 2021.

They made their stage debut on August 14, 2021 @KANDA SQUARE HALL.

The second line-up was announced on December 4, 2021.

The third line-up was announced in March 2022.

The fourth line-up was announced in August 2022.

The fifth line-up was announced on January 14, 2023.

Current Members

 * Kosaka Sena (香坂星奈) (Joined May 24, 2023)
 * Kouzuki Hana (香月はな) (Joined May 24, 2023)
 * Hinata Kotori (日向琴里) (Joined May 24, 2023)
 * Yukishiro Rina (雪白璃奈) (Joined May 24, 2023)

Former Members

 * Ishikawa Riona (石川里緒菜) (Founding member; withdrew July 22, 2021 )
 * YURINA (Founding member; withdrew September 12, 2021 )
 * Motoi Meme (本井めめ) (Founding member; withdrew September 28, 2021 )
 * Nagamiya Rea (永宮れあ) (Founding member; Graduated November 12, 2021)
 * Hinata Marino (日向まりの) (Founding member; Graduated November 12, 2021)
 * Hanasaki Lisa (華咲りさ) (Joined July 22, 2021 ; Graduated November 12, 2021)
 * Mashu (ましゅ) (Joined September 12, 2021 ; Graduated November 12, 2021)
 * Ide Ryoko (井出涼子) (Joined September 28, 2021 ; Graduated November 12, 2021)
 * Azuma Mashiro (東茉白) (Joined December 4, 2021)
 * Imada Miri (今田未莉) (Joined December 4, 2021)
 * Kishino Haruka (岸乃陽香) (Joined December 4, 2021)
 * Momose Haruka (百瀬はるか) (Joined December 4, 2021)
 * Nagisa (なぎさ) (Joined December 4, 2021)
 * Kishino Haruka (岸乃陽香) (Joined March 2022)
 * Ishikawa Ruu (石川琉) (Joined July 14, 2022)
 * Kasumi (かすみ) (Joined July 2022)
 * Nanase (七瀬) (Joined July 2022)
 * Sakurazawa Kotone (桜沢琴音) (Joined August 14, 2022)
 * Sakuraba Kaho (桜葉かほ) (Joined August 14, 2022)
 * Harupon (はるぽん) (Joined July 2022)
 * Kotoha (ｺﾄﾊ) (Joined June 2022)
 * Misaki Momoka (三崎桃果) (Joined August 14, 2022)
 * Misaki Rikka (みさきりっか) (Joined July 2022)
 * Anon (あのん; ) (Joined September 17, 2022)
 * Ichinose Nonoka (一ノ瀬ののか; ) (Joined September 17, 2022)
 * Sekai Kaju (世界かじゅ) (Joined September 17, 2022)
 * Tsukishiro Moka (月城もか; ) (Joined September 17, 2022)
 * Hoshimiya Uta (星宮うた; ) (Joined September 17, 2022)
 * Aimi Yuka (藍南ゆか) (Joined October 25, 2022, Graduated November 29, 2022)
 * Aizuki Shino (藍月しの) (Joined October 25, 2022, Graduated November 29, 2022)
 * Hazuki Risako (葉月りさこ) (Joined October 25, 2022, Graduated November 29, 2022)
 * Yuyuko (ゆゆこ; ) (Joined October 25, 2022)
 * Riria (りりあ) (Joined November 29, 2022)
 * Kayano Hika (茅野ひか) (Joined November 29, 2022)
 * Tachibana Ami (立花あみ) (Joined November 29, 2022)
 * Anzu (Joined December 28, 2022)
 * Okiku (おきく) (Joined December 28, 2022)
 * Kadota Nao (かどたなお) (Joined December 28, 2022)
 * Kokoro (こころ) (Joined December 28, 2022)
 * Matsuno Hazuki (松野羽月) (Joined November 29, 2022)
 * Inoue Sakura (井上咲愛; ) (Joined January 14, 2023)
 * Sakura Hono (佐倉帆乃; ) (Joined January 14, 2023)
 * Runa (月渚; ) (Joined January 14, 2023)
 * Tsukishima Mimika (月島美々花; ) (Joined January 14, 2023)
 * Hoshikage Rei (星影黎; ) (Joined January 14, 2023)
 * Ueno Yura (上野結愛) (Joined March 6, 2023)
 * Sasaki Nonoa (佐々木乃愛) (Joined March 6, 2023)
 * Niina (にいな) (Joined March 6, 2023)
 * Nishino Kotoha (西野琴羽) (Joined March 6, 2023)
 * Hoshino Mitsuki (星野美月) (Joined March 6, 2023)