Manga version of the Summer Wars movie.
When timid eleventh-grader and math genius Kenji Koiso is asked by older student and secret crush Natsuki to come with her to her familys Nagano home for a summer job, he agrees without hesitation. Natsukis family, the Jinnouchi clan, dates back to the Muromachi era, and theyve all come together to celebrate the 90th birthday of the spunky matriarch of the family, Sakae. Thats when Kenji discovers his summer job is to pretend to be Natsukis fiancé and dance with her at the birthday celebration. As Kenji attempts to keep up with Natsukis act around her family, he receives a strange math problem on his cell phone which, being a math genius, he cant resist solving. As it turns out, the solution to the mysterious equation causes a hijacking of the social networking site through which most of the world's social and business traffic flows.