Season 4

Furuhata investigates a series of bizarre, seemingly random accidental deaths. He zeroes in on the suspected murderer, but loses faith in his instincts when the suspect is himself killed. However, in the end, he ends up solving three murders and catching the real suspect.

Ichiro Suzuki, a baseball player obsessed with fair play, murders a man who was blackmailing his brother who is none other than Furuhata's faithful friend Mukojima.

Kyoko Kagami is a pen name for a pair of twin writers. After one sister kills the other, their technical advisor Furuhata investigates. His investigation is complicated by his feelings for the surviving sister.