Валькірія

Heroine of the series and a princess from Planet Valhalla, in the Dolphin Constellation. Once Valkyrie learned that her father was planning a political marriage for her without her consent, she fled to Earth and crash landed on Kazuto's bathhouse. In order to save his life she had to give half of her soul to him, but that process turned her into an 8 year old girl. She can only regain her normal form by kissing Kazuto but it doesn't last long and she normally kisses him in order to protect him. She eventually develops deep feelings of love for Kazuto. Her powers include flight, energy manipulation and defensive shields, plus she wields an artifact called the Key of Time.

When it is later revealed that Kazuto is the one that she will marry, she is overjoyed, but it is difficult for the ceremony to take place since she keeps on reverting back to her child form. At the end of the 3rd series, due to a mishap with the Princess Mural, Valkyrie's older and younger selves split into two separate people. During the 4th season, Valkyrie's former classmates mistake her younger self to be her daughter.