Teenage math whiz Kenji Koiso agrees to take a summer job at the Nagano hometown of his crush, Natsuki. When he arrives, he finds that her family have reunited to celebrate the 90th birthday of their matriarch. His job: pretend to be Natsuki's fiancé. Meanwhile, his attempt to solve a mathematical equation causes a parallel world's collision with Earth.
as Kenji Koiso (voice)
as Natsuki Shinohara (voice)
as Kazuma Ikezawa (voice)
as Sakae Jinnouchi (voice)
as Wabisuke Jinnouchi (voice)
as Takashi Sakuma (voice)
as Yukiko Shinohara (voice)
as Kazuo Shinohara (voice)
as Mariko Jinnouchi (voice)
as Riichi Jinnouchi (voice)
as Rika Jinnouchi (voice)
as Mansuke Jinnouchi (voice)
as Tasuke Jinnouchi (voice)
as Shota Jinnouchi (voice)
as Naomi Miwa (voice)
as Kiyomi Ikezawa (voice)
as Mansaku Jinnouchi (voice)
as Yorihiko Jinnouchi (voice)
as Kunihiko Jinnouchi (voice)
as Katsuhiko Jinnouchi (voice)
as Noriko Jinnouchi (voice)
as Nana Jinnouchi (voice)
as Yumi Jinnouchi (voice)
as Ryohei Jinnouchi (voice)
as Yuhei Jinnouchi (voice)
as Shingo Jinnouchi (voice)
as Mao Jinnouchi (voice)
as Kana Jinnouchi (voice)
