Feena is the princess of the Kingdom of Sphere on the moon and also the main female protagonist. In order to become more knowledgeable about Earth and be able to follow in her mother's footsteps, she comes to Earth in a homestay with the family of the primary secretary to the president of the United Nations, Sayaka Hozumi. Since she was very young, she has always wanted to know more about the Earth and some day she hopes to surpass her mother in trying to bridge the gap between the Earth and the Kingdom of Sphere. She is well educated in terms of literature and science and has great sword skills. However, she is somewhat naive in matters of the heart and has a tendency to jump into situations without thinking, (such as jumping into a river to save a drowning puppy, without knowing how to swim, and mistaking moths for aliens). Feena once came to Earth when she was a child, and met Tatsuya previously after her mother's death, in which Tatsuya tried to comfort her. She eventually falls in love with him and later marries him to finally bring peace between the Earth and the Moon.