One summer, mysterious supernatural phenomena begin appearing all across Japan, capturing the nation’s attention. Amid all the commotion, the Nohara family sets off for Akita Prefecture to visit Hiroshi’s hometown during their summer vacation. Unbeknownst to them, a suspicious figure watches them from the shadows of the garden. Looking forward to their long-awaited homecoming and the local fireworks festival, the Noharas spend a peaceful time at Grandpa Ginnosuke’s house. But the morning after they arrive in Akita, something inexplicable happens. Their room is mysteriously covered with flyers advertising “Obake-tion Village.” Excited by the promise of “All-you-can-eat Chocobi!”, Shinnosuke eagerly begs his family to take him there, and the Noharas decide to visit. As they travel through the ever-changing countryside of Akita, they stumble upon the forbidden entrance to the hidden Land of Yokai, a place no human is meant to enter.

After wandering into the Land of Yokai, Hiroshi and Misae are exposed as humans. As punishment, their “butt-balls” are stolen, transforming them into yokai themselves! Worse still, anyone who loses their butt-balls doesn’t just become a yokai, they also gradually lose all memories of their life as a human.