A nerd must fight powerful spirits and aliens all vying for the secret power of his “family jewel,” so who better to fight alongside him than his high school crush and a spirit granny?! Okarun, a high school boy obsessed with supernatural phenomena, is cursed by Turbo Granny! To break the curse, Okarun and his classmate Momo Ayase challenge Turbo Granny to a high-stakes race. But Turbo Granny’s assassin, a bound spirit in the form of a giant crab, has other plans! Okarun, a high school boy obsessed with supernatural phenomena, is cursed by Turbo Granny! To break the curse, Okarun and his classmate Momo Ayase challenge Turbo Granny to a high-stakes race. But Turbo Granny’s assassin, a bound spirit in the form of a giant crab, has other plans!