Overdevelopment and crowding in Japan has forced many of its indigenous spirits and ghosts to lose their homes. Due to problems caused by the homeless spirits, a new profession was created, the Ghost Sweepers (GS). Private exorcists for hire; they serve only the highest bidder to survive in the cutthroat corporate world. Among this, the Mikami GS Company, led by Reiko Mikami and her two assistants, the teenage boy Tadao Yokoshima and the ghost girl Okinu, is said to be the best.

Ghost Sweeper Mikami: Joreishi wa Nice Body is a side-scrolling platformer where the player controls Reiko through multiple stages. Reiko is armed with a magic baton that can be used to perform several types of melee attacks. The baton can be powered up to shoot various types of projectiles, though these powerups are lost if Reiko takes any damage. It can also be used as a type of grappling hook to access certain platforms. There are also limited uses of magic attacks that hit all enemies on the screen.