Z5-A1

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

The first line-up was announced on July 8, 2021.

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

The second line-up was announced on January 9, 2022 and debuted on January 15, 2022.

The third line-up was announced in March 2022.

The fourth line-up was announced on August 14, 2022.

Current Members

 * Okada Reiko (岡田怜子) (Joined March 6, 2023)
 * Sui (穂) (Joined December 28, 2022)
 * Hoshiai Rine (星合里音) (Joined March 6, 2023)
 * Hoshikage Rei (星影黎) (Joined March 6, 2023)
 * Mito Mizuki (水戸みづき) (Joined March 6, 2023)

Former Members

 * Sakura (さくら) (Founding member; withdrew July 22, 2021 )
 * Tachibana Kirari (橘きらり) (Founding member; withdrew September 25, 2021 )
 * Sato Aya (佐藤彩) (Founding member; Withdrew October 1, 2021)
 * Aoi Arata (蒼李あらた) (Founding member; Withdrew between October 26th and November 23, 2021)
 * Yamada Nao (山田菜緒) (Founding member; Graduated November 12, 2021)
 * Myuu (みゅう) (Joined July 22, 2021 ; Graduated November 12, 2021)
 * Shirano Koko (白埜ここ) (Joined January 15, 2022)
 * Mizuno Seira (富永セイラ) (Joined January 15, 2022)
 * Aino Momo (愛乃もも) (Joined January 15, 2022)
 * Saito Rika (齊藤莉歌) (Joined January 15, 2022)
 * Yukimiya Shigure (雪宮しぐれ) (Joined January 15, 2022)
 * Utada Yuzu (詩田ゆず) (Joined March 2022)
 * Saki (咲) (Joined March 2022)
 * Sakura (さくら) (Joined March 2022)
 * Utada Yuzu (詩田ゆず) (Joined March or April 2022)
 * Saito Rika (齊藤莉歌) (Joined March or April 2022)
 * Nishimura Himeno (西村姫乃) (Joined April 2022)
 * Nekoyashiki Aoi (猫夜色あおい) (Joined April 2022)
 * Runachi (るなち) (Joined April 2022)
 * Inoue Tsumugi (井上紬葵) (Joined July 14, 2022)
 * Hanamiya Ayaka (花宮あやか) (Joined July 14, 2022)
 * Umesaki Risa (梅咲りさ) (Joined August 14, 2022)
 * Nishina Akari (西奈あかり) (Joined July 14, 2022)
 * Hirata Mitsuki (平田みつき) (Joined July 14, 2022)
 * Amatsuka Mio (天使みお; ) (Joined September 2022)
 * Amuro Kotori (安室ことり; ) (Joined September 2022)
 * Onishi Meria (尾西苺梨愛; ) (Joined August 14, 2022)
 * Nakajima Motomi (中嶋元美; ) (Joined September 2022)
 * Miura Juri (三浦樹里; ) (Joined September 2022)
 * Miyata Yume (宮田有萌) (Joined October 25, 2022, Graduated November 29, 2022)
 * Rinka (凛華) (Joined October 25, 2022, Graduated November 29, 2022)
 * Tadano Honyon (只野ほにょん) (Jointed October 25, 2022, Graduated November 29, 2022)
 * Hikari (ひかり) (Joined October 25, 2022, Graduated November 29, 2022)
 * Nono (ﾉﾉ) (Joined October 25, 2022, Graduated November 29, 2022)
 * Kaburagi Meru (鏑木める) (Joined November 29, 2022)
 * Chida Kanon (千田果穏) (Joined November 29, 2022)
 * Hamabe Mizuka (浜辺美珠香; ) (Joined November 29, 2022)
 * Hinami Mira (日南心良) (Joined October 25, 2022)
 * Haneda Momone (羽田百奏音) (Joined November 29, 2022)
 * Yume (ユメ) (Joined December 28, 2022)
 * ei (Joined January 14, 2023)
 * Shirayuki Rina (白雪里奈) (Joined January 14, 2023)
 * Todoroki Shizuku (轟雫玖; ) (Joined December 28, 2022)
 * Kurumi (くるみ) (Joined December 28, 2022)
 * Hashimoto Akane (橋本あかね) (Joined March 6, 2023)