Arcana Heart takes place in Tokyo and revolves around the Earth and the Elemental world, both of which previously existed as one but were separated for unknown causes and now exists in parallel boundaries, which are becoming more ambiguous. Mildred Avallone of Ministry of Elemental Affairs wishes to remove the barrier and merge the two worlds together but doing so could prove catastrophic. Eleven young girls known as "Maidens", who possess the ability to communicate with beings from the Elemental world known as "Arcana", attempt to stop the event. Heart Aino is a normal high school student who shares a passion for animals, She is the main protagonist of the game. She also assists her mother in running the family-owned restaurant Cafe Aino, and hopes to one day make something that can be placed on Cafe Aino's menu. Her Arcana is
Partinias, the Arcana of Love. An angel with two pairs of wings who can manipulate light, she is Heart's partner and friend. • : Kira Daidohji is a child prodigy who earned a doctorate in elemental science at a prestigious American university, but on her return to Japan, was forced to attend
elementary school. This made her bitter and she became arrogant and condescending, deciding to embark on a quest for world domination. She was invited by the Rosenberg branch to monitor spirit disasters in Japan. She fights using a giant semi-solid blob which she controls through her Arcana, the leviathan
Niptra, the Arcana of Water. • : Lilica Felchenerow is the daughter of a human mother and a demon father. She enjoys skipping school and skating around town on the roller blades her father bought her, which she enhanced with ether-powered motors. Her Arcana is
Tempestas, the Arcana of Wind, who was once gravely wounded but nursed back to health by Lilica. • : Yoriko Yasuzumi is introverted, bookish, and fascinated with the occult. One night, with Lilica's help, she decided to try to summon a low-level demon servant for herself. As a prank, Lilica re-drew the magic circle, and Yoriko summoned Mike, the self-proclaimed "Demon King". A contract was formed between the two of them, and now she is unable to part with him. Her Arcana is
Dieu Mort, the Arcana of Death. He was formerly a man sentenced to be executed known as the "God of Death". • : Lieselotte Achenbach, the "Crimson-Eyed Criminal", became a cold-hearted assassin after losing her family. She travels the world alone, accompanied only by a leg-less ball-jointed puppet which carries the consciousness of , her older sister. Her Arcana is
Gier, the Arcana of Shadow, a creature composed of purely negative emotions that Lieselotte summons with drops of her own blood. • : Fiona Mayfield hails from a wealthy family in Britain. She became good friends with Saki (who came to Britain as an exchange student from Japan) until one fateful day when they were both sucked into the Elemental world. Saki managed to escape, but Fiona was trapped and now seeks to find a way back home, with the help of Mildred. Her Arcana is
Oreichalkos, the Arcana of Metal, a reptilian beast believed to be the oldest Arcana in existence. • : Mildred Avallone is the main antagonist and final boss of the game. Formerly the chief secretary of the Ministry of Elemental Affairs, her ambition is to merge the human and elemental worlds and attain god-like powers. She uses all of the characters' Arcanas. == Development ==