Moonlight Sword is a sword weapon item which is acquired when completing the Game Design questline which may only be started near the beginning of the game. It should be noted that the opportunity to obtain this weapon is potentially missed if the player does not speak with the Mech Design Man at the Raejack Village Inn before completing the Grass Temple.

It is the final reward in the questline and is only obtained after clearing all of the temples and saving Dotnia. It is received only after these conditions are met by talking to the Mech Design Man in FROM cave.