* AdaptationFirst: The manga adaptation came out before the movie.
* CelebrityVoiceActor: Most of the main characters are voiced by celebrities in the original Japanese version. For example, Kenji Koiso is voiced by Ryunosuke Kamiki, Natsuki Shinohara is voiced by actress and model Nanami Sakuraba, Kazuma Ikezawa is voiced by Mitsuki Tanimura and Sakae Jinnouchi is voiced by yakuza film star Sumiko Fuji.
* ChildrenVoicingChildren: In the Japanese version, Yuhei, Shingo, Mao and Kana were played by real-life child actors Rikito Ota, Yuki Imai, Creator/SumireMorohoshi and Hinano Minagawa, respectively.
* CrossdressingVoices: Mitsuki Tanimura and Maxey Whitehead as Kazuma Ikezawa.
** The English dub was directed by Creator/MikeMcFarland, who voiced Shota Jinnouchi.
** The Mexican Spanish dub was likewise directed by Yumi Jinnouchi's voice actress, Karla Vega.
* RecycledScript: Viewers who previously watched ''Our War Game'' will probably note the similarities between movies. The reason: both were written by Mamoru Hosoda.
* SpiritualSuccessor: Of ''[[Anime/DigimonAdventure Our War Game]]''.
* WhatCouldHaveBeen: News revealed that ''Summer Wars'' was rejected by Creator/WarnerBros... in which case, an entirely new dub would've had to be made! Who knows how much the chances of an Oscar nomination would've changed if that had happened!
* TheWikiRule: [[http://summerwars.wikia.com/wiki/Summer_Wars_Wiki Summer Wars Wiki.]]