
Plot
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.
Trailer
Cast

Ryunosuke Kamiki
Kenji Koiso (voice)

Hitomi Miyauchi
Natsuki Shinohara (voice)

Mitsuki Tanimura
Kazuma Ikezawa (voice)

Sumiko Fuji
Sakae Jinnouchi (voice)

Ayumu Saito
Wabisuke Jinnouchi (voice)

Takahiro Yokokawa
Takashi Sakuma (voice)

Kiyomi Tanigawa
Yukiko Shinohara (voice)

Mutsumi Sasaki
Kazuo Shinohara (voice)

Mieko Nobusawa
Mariko Jinnouchi (voice)

Takuya Kirimoto
Riichi Jinnouchi (voice)

Sakiko Tamagawa
Rika Jinnouchi (voice)

Ichiro Nagai
Mansuke Jinnouchi (voice)

Takashi Kobayashi
Tasuke Jinnouchi (voice)

Yutaka Shimizu
Shota Jinnouchi (voice)

Kaori Yamagata
Naomi Miwa (voice)

Tagame Tamura
Kiyomi Ikezawa (voice)

Tadashi Nakamura
Mansaku Jinnouchi (voice)

Yoji Tanaka
Yorihiko Jinnouchi (voice)

Hashiya Nakamura
Kunihiko Jinnouchi (voice)

Mitsutaka Itakura
Katsuhiko Jinnouchi (voice)

Eiko Kanazawa
Noriko Jinnouchi (voice)

Chigusa Takaku
Nana Jinnouchi (voice)

Riisa Naka
Yumi Jinnouchi (voice)

Naoto Adachi
Ryohei Jinnouchi (voice)

Rikito Ota
Yuhei Jinnouchi (voice)

Yuki Imai
Shingo Jinnouchi (voice)

Sumire Morohoshi
Mao Jinnouchi (voice)

Hinano Minagawa
Kana Jinnouchi (voice)