Some day in the near future, the crew of an "idol" (a popular culture star) takes a ride on the bus through the countryside. One of the female crew members unexpectedly faints and is taken by her friends into an abandoned mansion discovered nearby. Very soon, however, the accident begins to repeat itself, and evidence of a gruesome murder and possible ghostly presence in the mansion surfaces. Mei Star, an investigator with the team, and her computerized holographic assistant Navi must solve the mystery before it becomes too late.

Private eye dol is an adventure game played for the most part from a top-down perspective. The player navigates Mei around the playable environment, examines places and items of interest, and talks to other characters. With a few exceptions, there are no puzzles in the game, and the plot is advanced by triggering events. On several occasions items must be picked up, but they are used automatically in correspondent locations.