خلاصه داستان : کنجی کویسو، دانش‌آموز کلاس یازدهم و نابغه ریاضی در تلاش برای حل یک معادله ریاضی باعث تصادم یک دنیای مجازی (OZ) با زمین می شود...

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.