A Mogura Star Man is a space character from the very popular TV show "Masked Yaiba" that everyone one in the Detective Boys likes. What does the Mogura Star Man have to do with this episode's case? Conan, Genta, Mitsuhiko and Ayumi decide to play softball on a field where a mansion is supposed to be built, but postponed. But the ball that Genta hit flew over a fence and landed on the next door neighbor's yard. They didn't even get the change to get the ball when out from the haunted house-like mansion comes a man. No matter how much the gang trys, the man refuses to return the ball. Hopeless, the gang returns to Mouri Detective Office where they receive a shock when they hear the story behind the job that Kogoro accepted, to search for a missing sister.

Conan, Genta, Mitsuhiko, and Ayumi are playing softball in a postponed contruction site when Conan notices a man looking from the house next door into the field. Then Genta hits the ball over the fence into the yard of the house next door. When the gang try to get the ball, a man comes out and yells at them and refuses to get the ball for them. The gang goes back to Conan's place to get some food but find a man standing in from of the the Mouri Detective Office. The man,Masao Kouda, wanted Kogoro to find his sister who he thinks was murdered by Yoshikazu Watanuki, the man who's yard the Detective Boys hit the ball into. Kouda wants Kogoro to help him find his sister's body, but Kogoro replies that he can't because there isn't solid proof of a murder by Watanuki.