Felia

The main heroine. She is a mysterious girl with blue hair and red eyes that Sogo found in a cave. She has powers of telekinesis.

[Spoiler] It is later revealed that she is the embodiment of the planet. [/Spoiler]

[Spoiler] She eventually falls in love with Sogo. [/Spoiler]

[Spoiler] Both Felia and Sogo confess their feelings to each other in the final episode, where she sacrifices her life to save the planet and Sogo and leaves behind a pink gem as memory for Sogo promising him that she will always be with. Later a pink star lighting up in the sky, always shines above Sogo, marking the presence of Felia. [/Spoiler]

(Source: Wikipedia)