"Folklore" was announced at E3 2006 which was said to be "The next generation of dark fantasy." It was to be developed by Game Republic, under Yoshiki Okamoto, a video game designer who worked on popular games, including "Resident Evil". The game was originally titled "Monster Kingdom: Unknown Realms", and was intended as a companion piece to Gaia's '. However, disappointing sales of "Jewel Summoner" led to the game being retitled "Folklore". Gaia however would assist the development of Folklore, contributing monster designs. Numerous creatures appearing in "Folklore" would later appear in Gaia's PlayStation Portable game ' the following year, which also featured connectivity with "Folklore".