The kingdom of Prawfair faces a great crisis, with both princess heirs missing, an impending civil war, and a dangerous monster attacking every nightfall. Disguised as a commoner to escape her duties, Princess Charlotte is unaware she may be at the center of all these events. To avert a greater crisis, the young heroes must aid the nobility of this decaying realm and prove once and for all that they are the destined heroes. Traitors, villains disguised as heroes and vice versa, realms on the brink of collapse, arranged marriages, even more dangerous new enemies, entities with semi-divine powers, mysteries to be unraveled, mysterious monsters attacking cities, and a princess who could be the key to unleashing the Demon Emperor. An ancient evil stirs in the depths; who will survive this epic-scale clash? How will this change the fate of Fantastinen? Will the ordinary world also be in danger?

An ancestral power, belonging to a parallel world, is passed on to those worthy of being the bulwarks in the fight against the forces that threaten the balance. These valiant warriors were known as the "Sweks Hyewds", which in ancient language means the "six warriors", with powers passed through crystals called "Kerds". Without having any knowledge about it, six young anime fans end up receiving mysterious crystals from a strange little girl and thus shoulder the responsibilities acquired together with such power.