Moon. is a Japanese adult 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 girl who joins an 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. Much of the staff that created the game later became the founding members of the visual novel brand Key. Moon. was the starting point for Key's origins, and was the first time the principal Key team was formed. A novel based on the game written by Midori Tateyama was released in July 1998 by Movic. The game's original soundtrack was released bundled with Dōsei's soundtrack in August 2000 at Comiket 58; Dōsei was Tactics' first game. Moon. has been referenced in other media not directly related to the game, such as in Tactics' third game One: Kagayaku Kisetsu e, and in the second anime adaptation of Key's first game Kanon.