is a Japanese adult horror visual novel developed by Tactics, a brand of Nexton, released on November 21, 1997, playable on Windows PCs.

[1] 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 predetermined scenarios with courses of interaction, and focuses on the three female main characters.

[2][3] Moon is set within a windowless facility owned and operated by the Fargo religious organization that aims to research what is referred to as the "unseen power".

Outside of the living quarters, all believers have access to a dining hall, and are allowed to freely move within the confines of their own facility.

Training of believers takes the form of repeated visits to both the Minmes and Elpod rooms which contain devices able to interface with the trainee's mind.

The Elpod device makes trainees face a duplicate of themselves, forcing them to reminisce on past disgraces to again measure their mental strengthening.

Throughout the game, the player encounters CG artwork at certain points in the story, which take the place of the background art and character sprites.

Throughout gameplay, the player is given multiple options to choose from, and text progression pauses at these points until a choice is made.

The game's story is divided into 20 days each with an English subtitle displayed mostly in white with a portion of it colored red.

A few days later, Haruka—now under the influence of the unseen power—is ordered to kill Ikumi, but the power deserts her before she can do it, causing Haruka to go into hiding within the facility.

However, Ikumi is then put in a holding cell, but she is freed by her roommate who is not human but an entirely different species first encountered 30 years prior.

Ikumi spends several days in deep depression, but when she uses the Minmes device, she receives encouragement from the young man who now only exists as a memory, allowing her to track down Fargo's founder, known only as the "voice's owner".

[5] Planning for Moon was headed by Jun Maeda, who also worked on the game's scenario with fellow writer Naoki Hisaya.

[5] Art direction and character design was provided by Itaru Hinoue, while the computer graphics in the game was supplemented by Miracle Mikipon and Shinory.

[7] AI System published the game under the title Moon Memorial Selection on September 14, 2000, for a cheaper price.

[4] The DVD edition, and subsequent releases, also included full voice acting, two animated sequences at the beginning of the game, and improved graphics.

[4] A CD-ROM version of the DVD edition titled Moon CD LimitedEdition was released on three CDs on September 20, 2002.