- Aoi Morikawa (Princess Maison) as Kanna Tajima, a classmate of Yamada's who seems unconditionally kind to him
- Shuhei Uesugi (One Week Friends) as Kannonzaki, Haruna's boyfriend who bullies Yamada
- Shiori Doi (Children of Iron) as Rumi Koyama, Haruna's friend who gets pregnant but doesn't know who the father is
- SUMIRE as Kozue Yoshikawa, a model with an eating disorder who grows closer to Haruna and Yamada
Lastly, the film's theme song "Arpeggio (Surely It's Beyond the Magic Tunnel)" and is performed by Kenji Ozawa. Directed by Isao Yukisada (In the Center of the World) and is set for a February 16, 2018 release.
[Source: Anime News Network]