Birthday: August 8
Blood type: O
Height: 4'9" or 145cm
Status: Magic Knight/pillar
Favorite food: ice cream
Least favorite food: anything spicy
Favorite color: red
Favorite subject: biology
Least favorite subject: music
Hobby: playing with her dog Hikari
Specialties: kendo, talking to animals
Extra curricular activities: Kendo Club
Wants to be: a dog trainer
Hikaru is one of the three Magic Knights summoned to Cephiro by Princess Emeraude; the knight of fire (as her names implies. Hikaru means "Light of the Lion Shrine").
She is the smallest of the three knights, often mistaken for an elementary student and considered a bit tomboyish by her classmates. Despite her height, and her apparent naïveté, she can be quite fierce and strong when the needs calls for it. Underneath her ever-present smiles and innocence, there lies a the spirit of a warrior who is determined to protect her friends and everyone's happiness. Even at the cost of her own.
Because of this, as the series evolves, she is the one who is most affected—physically and mentally—by all the brutality and war around her. Nonetheless, Hikaru keeps a strong facade, trying not to worry Umi and Fuu who she considers her most precious friends, despite only having met them moments before being dragged into Cephiro.
As the true reasons for their summon come to light, and Hikaru is forced to act with Umi and Fuu to kill both Zagato and a grief-stricken Emeraude, her heart overflows with pain and self-hate and she unwittingly burns a shadow—Nova—across the surface of Cephiro before being transported back to Earth.
During the second season, she is forced to battle her other self-Nova is vengeful and maliciously possessive of her, causing more heartache and troubles—and her own blooming feelings for Kail Lantis.
At first, Hikaru approaches him, feeling guilty for the death of his brother, and begs him to hate only her, to hit only her but not to hurt Umi or Fuu. The moment Lantis tells her that she shouldn't blame herself, as it wasn't her fault but destiny, is most likely the moment when she starts falling for him. Without knowing it.
Throughout the entire second season, she and Lantis are brought together many times, by circumstances, and it is not until Nova points out that she is very much in love with Lantis that Hikaru realizes it herself.
After a grueling battle, in her own mind, to reforge the sword that Nova managed to break, Hikaru comes out victorious and, on the verge of blacking out in Lantis's arms, confesses to him that she loves him. She does not remember it after she wakes up but the feelings are still alive in her heart and Nova takes advantage of them time and time again.
Despite the animosity between Cephiro and the three invading countries, she manages to befriend Eagle Vision of Autozam, making Eagle a sort of bridge between both his friends.
At one point in the anime, Eagle and Hikaru both become candidates for the Pillar position but it is Hikaru who is chosen in the end and makes a wish to rid Cephiro of its oppressive system; wishing for Cephiro to be created by all those who love it.
In the manga, Hikaru's feeling for Lantis is less mature and she likes both Lantis and Eagle Vision. When Lantis asked her in final chapter who she wants to marry, she answered, that she wants to marry him and Eagle. Also bond between Hikaru and Eagle Vision is stronger in manga, because in manga she fought with him for the position of the Pillar, defeated him and then saved his life against the will of the Creator.
(Source: Magic Knight Wikia)