Private eye Bannai Tarao (Chiezo Kataoka) and his assistant Masako (Chizuru Kitagawa) investigate the mysterious murder of a baseball player who was killed in the middle of a game.

First Moonlight Mask theatrical film.

The body of a woman was found in a manhole. Is it an affair? The victim is a clerk at a mannequin manufacturing company. At the age of 26, she was a widow with a child, and she went missing after he went to collect her salary from the bank. A colleague at work said the victim was wearing an opal ring, but the bank clerk says she wore a jade ring when he came to withdraw money.