22/7: 8＋3=?
Type: Special, Episodes: 1
Aired: Sep 16, 2020
Studio: A-1 Pictures
Source: Other
Rating: PG-13 - Teens 13 or older
Synopsis:
Thirteenth episode included in sixth Blu-ray volume.

This episode centers on the story of Mikami Kamiki, Yuuki Toujou, and Tsubomi Hiiragi.

(Source: Official Website)