Heroes Phantasia is a game released for the PlayStation Portable, where the player can control a great variety of characters from 10 different anime series of the last 10 years, as well as some original characters.

In a world much like our own, numerous troubling incidents occur all over the planet. People known as Native Alters with strange powers instigate anti-social acts. Monstrous creatures called Orphan are meddling in human society. Equally monstrous beings known as Chiropterans cause a rash of vampire-related murders, and several resurrected historical figures attack the U.S. Library of Congress. In order to counter all of the above, several organizations rise up to fend off these threats and maintain peace and order: Holy, HiME, Red Shield, and the Special Operations Division of the British Library.

Meanwhile, the dimensional walls around the world of Adloaz have collapsed, and all kinds of monsters have started to appear across the world. Fortunately, the fall of the dimensional walls also ushered in a band of heroes: Orphen, Louie, and Lina Inverse.

And elsewhere, a group of frog-shaped aliens have been sent here from planet Keron to perform a reconnaissance of our planet, and if possible, conquer it.