Planeptune is the land blessed with the CPU Purple Heart's protection. When she cannot be there to run it, Histoire takes her stead. Despite its advanced technology and civilization, it is the land most ravaged by monsters. Some believe their goddess was once defeated by an overlord, creating a rift in Planeptune´s protection and causing an increase in monster attacks. To add credence to these beliefs, the CPU Purple Heart has not been seen by her people in over three years.
- It is the only nation whose name does not begin with a "L".
- Many side story cutscenes on this landmass contain references to SEGA games.
- Based on Neptune's hardware specifications, it can be said that her console is the most advanced. This may explain why Planeptune is the most technologically advanced in comparison to the other landmasses.
- One of the Lost Places in Planeptune in Victory, "The Golden Axe", may be a reference to the "Golden Axe" games for the Sega Genesis.