Nishimura Kyoutarou Mystery: Hokutosei no Onna

Hokutosei no Onna (the title refers to the express train connecting Tokyo and Hokkaido in Japan rather than the Ursa Major constellation) is based on the works of the Japanese detective story writer Kyōtarō Nishimura, starring Inspector Totsugawa and his assistant Kamei, who is the protagonist of the game. A man was found stabbed to death in his apartment in Tokyo; shortly after the investigation begins, another man is killed in a hotel room in Hokkaido. Kamei must question witnesses and suspects and examine evidence in order to solve the mystery.

[from MobyGames]