is a Japanese manga series written and illustrated by Sae Amatsu, published from 2001 to 2005 in Monthly Shōnen Ace. An OVA series was released in 2003, with three sets of episodes. Two years later, a new OVA series was released, named "Guardian Hearts - Power Up". Brief summary A guardian heart by the name of Hina accidentally reveals herself to a boy. The two then begin living together. As the story progresses, more girls begin living with them for the same reason. Characters Voiced by: Takahiro Sakurai The male protagonist of the show. Fortunately, or perhaps unfortunately, he discovers the secrets and identities of a number of girls throughout the series. The first girl being the Guardian Heart, Hina, and to keep her identity secret he has no choice but to let her live with him. To make matters more interesting, every girl whose secret or identity he discovers also comes to live with him and Hina. Voiced by: Rie Kugimiya One of the main female characters. She is a Guardian Heart, a protector of the peace and well-being of an assigned planet, who must always keep her identity a secret. Hina is sent to Earth as a last chance to redeem her previous failures at keeping her identity a secret (said to be equal to a record). This fails spectacularly as Kazuya witnesses her arrival (thus setting a new record for the fastest that a Guardian Heart's identity has been found out). She asks Kazuya to let her live with him (since he has seen her naked) so that they can pretend to be a family and so her allow her to stay, since family members are exempt from the keeping her identity secret requirement. Kazuya's mother who arrives on the scene a little later agrees to this arrangement over his strenuous objections. In addition to her duties she also has to complete tests given by her superiors so that she can stay on Earth. She loves Kazuya and pushes the other girls away when she feels they're getting too close to him. Voiced by: Haruna Ikezawa One of the main female characters. She is a princess from a magical world who came to Earth looking for a husband who is also secretly a magical girl. After her accidental meeting with Kazuya she becomes convinced that he is fated to become her husband, especially since Kazuya found out