Z4-A5

 is a group within Zero Project. The theme of the group is K-Pop.

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

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

The second line-up was announced in March 2022.

Current Members

 * Usami Seina (宇参星恋) (Joined July 2022)
 * Kotoha (ｺﾄﾊ) (Joined July 2022)
 * Shigeta Norika (重田紀果) (Joined July 2022)
 * Nanaka (ななか) (Joined June 2022)
 * Maria (まりあ) (Joined July 2022)

Former Members

 * Maishi Makoto (舞石まこと) (Founding member)
 * Airu (あいる) (Founding member)
 * MIWOO (ミウ) (Founding member)
 * Myuu (みゅう) (Founding member)
 * Kinu (きぬ) (Founding member)
 * Kisumi Megu (姫菫めぐ) (Joined March 2022)
 * hinano (Joined March 2022)
 * Uyugu (うゆぐ) (Joined March or April 2022)
 * Kusaka Hiiro (日下緋彩) (Joined March 2022)
 * Seru (セル) (Joined March 2022)
 * Minazuki Reine (水無月黎音) (Joined March or April 2022)
 * Aizu Mei (藍住明以) (Joined June 2022)
 * Kaito (カイト) (Joined June 2022)
 * Minazuki Reine (水無月黎音) (Joined June 2022)
 * Rui (るい) (Joined June 2022)