8+3=?

8+3=? is the bonus thirteenth OVA episode of the 22/7 anime series. The episode was originally only available in the limited edition release of the anime's Blu-ray & DVD Vol.6. It was originally scheduled to be released on August 26, 2020, but had been delayed to September 16, 2020.

Summary
22/7 make a comeback in front of their fans on 12/24, which is the anniversary of when they formed the group. The next day the eight members gather at the agency, where they discover that the Wall has been completely restored to its original state. As the mystery deepens, Sakura proposes a Christmas party to celebrate the reunion of the group and to clear out any bad vibes. Suddenly three strangers enter the room. They are wearing the same uniform as the eight members, and they introduce themselves as Mikami Kamiki, Yuki Tojo, and Tsubomi Hiiragi. They claim that they are new members gathered by the Wall.

Cast

 * Nagomi Saijo as Miu Takigawa
 * Sally Amaki as Sakura Fujima
 * Mizuha Kuraoka as Miyako Kono
 * Chiharu Hokaze as Reika Sato
 * Ruri Umino as Jun Toda
 * Kanae Shirosawa as Akane Maruyama
 * Reina Miyase as Ayaka Tachikawa
 * Uta Kawase as Nicole Saito
 * Moe Suzuhana as Mikami Kamiki
 * Urara Takatsuji as Yuki Tojo
 * Aina Takeda as Tsubomi Hiiragi