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Summer Wars

7.5PG

MovieAnimation, Science Fiction20091h 54m

Always protect your network.

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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Summer Wars poster

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.

Directed by
Mamoru Hosoda
Written by
Satoko Okudera
Genres
Animation, Science Fiction
Released
August 1, 2009
Runtime
1h 54m
Status
Released
Original title
サマーウォーズ
Language
Japanese
Countries
Japan
Studios
Madhouse, Nippon Television Network Corporation, KADOKAWA Shoten, D.N. Dream Partners, Warner Bros. Japan, Yomiuri Telecasting Corporation, VAP, Studio Chizu
Box office
$18,434,328
  • Ryunosuke KamikiKenji Koiso (voice)
  • Hitomi MiyauchiNatsuki Shinohara (voice)
  • Mitsuki TanimuraKazuma Ikezawa (voice)
  • Sumiko FujiSakae Jinnouchi (voice)
  • Ayumu SaitoWabisuke Jinnouchi (voice)
  • Takahiro YokokawaTakashi Sakuma (voice)
  • Kiyomi TanigawaYukiko Shinohara (voice)
  • Mutsumi SasakiKazuo Shinohara (voice)
  • Mieko NobusawaMariko Jinnouchi (voice)
  • Takuya KirimotoRiichi Jinnouchi (voice)
  • Sakiko TamagawaRika Jinnouchi (voice)
  • Ichiro NagaiMansuke Jinnouchi (voice)
  • Takashi KobayashiTasuke Jinnouchi (voice)
  • Yutaka ShimizuShota Jinnouchi (voice)
  • Kaori YamagataNaomi Miwa (voice)
  • Tagame TamuraKiyomi Ikezawa (voice)
  • Tadashi NakamuraMansaku Jinnouchi (voice)
  • Yoji TanakaYorihiko Jinnouchi (voice)
  • HHashiya NakamuraKunihiko Jinnouchi (voice)
  • Mitsutaka ItakuraKatsuhiko Jinnouchi (voice)

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Availability for your region. Streaming data provided by JustWatch.

  • CinemaSerf★ 7August 6, 2025
    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 manages just about ev…Read more

    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 manages just about everything we do - from using our phones to firing a nuclear missile. It’s bright spark - but maybe just a touch inept - “Kenji” who has accepted a task that is definitely not what he was expecting from “Natsuki” and so finds himself at her grandmother’s ninetieth birthday luncheon posing as her beau. A bit of a nervous wreck, he is later presented with an online puzzle by “OZ”, the network in question and he manages to message back a solution. Next thing we all know, it’s been hacked by an increasingly violent AI that is bent on a quest for knowledge and power, and that will stop at nothing. When poor old “Kenji” is identified and gets the blame, only an unique sort of intervention from granny and a solid series of team efforts from her family and from his friends might enable them to thwart this menacing creation. The animation starts off with images that reminded me of one of those childhood kaleidoscopes that brought vibrant crystalline shapes together, before heading full pelt into a frequently quite pithily comedic look at family traditions, teenage hormones and menacing nasties threatening the entire fabric of the internet. You’ll possibly never see a more potent cinematic demonstration of just how dependent and inter-dependant we are on this network of cables and zeroes and ones for much, if not most, of modern life. Not just our social lives, but our actual lives too are controlled and once control of that falls into malevolent hands, well humanity risks being well and truly stuffed. The last half hour focuses a little more on dealing with that problem, and the quickly paced action animation is underpinned by a plausible degree of science too. In many ways, it’s almost a horror movie - especially if you think on it: first love or online demons?

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