Review: Summer Wars (Hosoda Mamoru)

High-schooler Kenji just missed representing Japan in the Math Olympics, so this summer he has nothing to look forward to except working as a low-level moderator for OZ, the nation's premiere virtual reality social, business, and governmental networking site, with his friend Takashi. That is, until his classmate Natsuki persuades him to accompany her to her great-grandmother's 90th birthday party at the family's run-down country house, where he is unexpectedly introduced to the clan as her fiancé. Against his better judgment, Kenji goes along with the story, but matters take another unexpected turn when he solves a tricky math puzzle sent to his OZ account in the middle of the night. Next morning, he discovers that his account has been used to hack dozens of others, including those of government officials, with dire real-world results. But as Japan descends into chaos, Natsuki's great-grandmother picks up the phone and begins making calls to her own social network ... and her family once again finds itself on the front line of war ...

( Spoilers ho! )