GS Mikami Gokuraku Daisakusen!!

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.

(Source: Wikipedia)

Included one-shot:
Volume 1: Gokuraku Mouja (Ghost Sweeping in the Haunted Mansion)