Summer Wars

2009 114 min ★ 7.5 Animation, Science Fiction

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.

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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)

Details

Director

Mamoru Hosoda

Screenplay

Satoko Okudera

Tagline

"Always protect your network."

Status

Released

Original Language

JA

Revenue

$18,434,328

Production

Madhouse, Nippon Television Network Corporation, KADOKAWA Shoten, D.N. Dream Partners, Warner Bros. Japan, Yomiuri Telecasting Corporation, VAP, Studio Chizu

Reviews

C

CinemaSerf

August 6, 2025

★ 7/10

It’s really quite apposite to watch this film at a time when governments across the world are merrily acquiescing to the demands of global tech to facilitate the rampant advance of AI. This story quite cleverly illustrates just how easily a collection of “Will Hunting” types can be used to crack even the most complex (2,000 digit) numeric code and allow nefarious access to a global network which m...