Moon is a Japanese adult horror visual novel developed by Tactics, a brand of Nexton, released on November 21, 1997, playable on Windows PCs. The game was described by the development team as a "Reaching the Heart AVG" . The story follows the protagonist Ikumi Amasawa, a teenage girl who joins a mysterious organization called Fargo in the hopes of discovering why and how her mother died, who was a member of the same group. The gameplay in Moon follows a branching plot line which offers pre-determined scenarios with courses of interaction, and focuses on the three female main characters. The game ranked twice in the national top 50 for best-selling PC games sold in Japan.

Key is a Japanese visual novel studio known for making dramatic and plot-oriented titles. It was formed on July 21, 1998, as a brand under the publisher Visual Arts, and is located in Kita, Osaka.