Takakura Ken is a boy who got cursed by the "Turbo Grandma" ghost. The only way to relieve the curse is by luring the ghost out of her comfort area through some kind of a race.
Takakura believes in UFOs and made a bet with Ayase (who believes in ghosts but not UFOs) to see whether UFOs or ghosts are the ones that are real.
The bet results in Takakura getting cursed by a ghost and Ayase getting kidnapped by aliens.
Takakura was nicknamed "Okarun" by Ayase because the name "Takakura Ken" is the same name as her favorite actor.
