Takeshi Saitō is a 24-year-old security guard working for the Teikoku Sōsei conglomerate. One day he is transferred to a large theme park called "Fantasian" and owned by the company. There he becomes one of the guards donning a medieval knight's costume. At first he is excited to meet his co-workers, most of which are young attractive women. However, after a few days one of the employees dies in an accident seemingly caused by a system malfunction in one of the amusement devices. As more people begin to die under mysterious circumstances, Takeshi realizes these deaths may not be accidental, and tries to find a connection between them and the disappearance of the park's main architect.

The sequel to Ryōki no Ori features a different protagonist and character cast, and is not directly connected to its predecessor story-wise. Gameplay similarities are manifested in the visual novel-like structure of both games. The game's plot advances and branches into different directions depending on the locations the player chooses to visit and the choices made by him when prompted. Unlike the previous game, this installment allows top-down navigation between first-person-view locations. Each visit advances the game's internal clock, and it is often crucial to the plot to be in a certain place at a certain time. These choices also have an impact on Takeshi's relationships with female characters (which can be evaluated by a fortune teller), adding a more pronounced dating element to the gameplay.