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.

Current Members
None currently

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)