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.
神木隆之介
as Kenji Koiso (voice)
宮内ひとみ
as Natsuki Shinohara (voice)
谷村美月
as Kazuma Ikezawa (voice)
富司純子
as Sakae Jinnouchi (voice)
斎藤歩
as Wabisuke Jinnouchi (voice)
Takahiro Yokokawa
as Takashi Sakuma (voice)
谷川清美
as Yukiko Shinohara (voice)
佐々木睦
as Kazuo Shinohara (voice)
信澤三惠子
as Mariko Jinnouchi (voice)
桐本拓哉
as Riichi Jinnouchi (voice)
玉川砂記子
as Rika Jinnouchi (voice)
永井一郎
as Mansuke Jinnouchi (voice)
