- Tsuyoshi Furukawa as Yukihiro
- Koudai Matsuoka (Tokumei Sentai Go-Busters, Naruto The Live Spectacle) as Itsuki Kaga, Souta's handsome but oddball cousin
- Karin One as Aki Nishino, Souta's younger sister who is a video game otaku
- Jun Fukuyama (Code Geass) as Haginosuke Tachibana, a character made for the project and is a manager of the Happy Dogs dog cafe where Souta's younger sister Aki part time, and often gives Souta romance advice
The original manga follows the relationship between old-fashioned and domestically minded high school girl Mai Nanase and her brother's friend, the innocent late bloomer Souta Nishino. Mai and her brother's room are adjacent to each other, with thin walls that allow them to overhear each other. The story begins when one day, she overhears Sota telling her brother that he finds her cute.
The upcoming film is directed by Ryo Nakajima (Samurai Rock) with scripts written by Chieko Nakagawa (Closest Love To Heaven). The film is set for a May 26th release.
[Source: Anime News Network]