Okitegami Kyouko is a famous detective who solves cases in a single day. In fact, she has to, since her memories only last for one day before they 'reset.' However, for important things, she writes messages for herself down on her body with a special pen. One of her common clients is Kakushidate Yakusuke, a man who is often wrongly suspected of committing crimes. There is also a live-action drama adaptation of this story.

Adapted from the "Boukyaku Tantei" light novel series.