Summer Wars

Kenji Koiso, a shy eleventh-grader with a gift for mathematics, agrees to spend the summer with Natsuki, an older student he secretly likes, at her family’s home in Nagano. There, he learns that his supposed summer job is to pose as Natsuki’s fiancé during a gathering for her family’s spirited 90-year-old matriarch, Sakae. The Jinnouchi clan traces its history back to the Muromachi era, and Kenji must keep up the act among its many relatives. When Kenji solves a mysterious mathematical problem sent to his phone, the answer helps trigger a crisis in a virtual world that spills into reality. He and his newly acquired fake family must work together to restore order.