ANSATSU KYOUSHITSU 2: KAGAIJUGYOU-HEN

Shorts of Ansatsu Kyoushitsu (TV) 2nd Season which adapt chapters of the manga which are not in the TV series. The adapted chapters are 78 ("Takebayashi no Jikan") and 79 ("Shihaisha no Jikan, Ni Jikanme"), which are published in the ninth manga volume. — Description from AniList community (anilist.co).