Comet Lucifer

On the planet Gift there are precious crystals called Giftjium buried in the earth. A young man named S?go lives in Garden Indigo, a prosperous mining town. S?go's hobby is to collect rare crystals. One day, he gets wrapped up in a riot caused by his classmates Kaon, Roman, and Otto, and he loses his way until he finds a lake deep under the ground's mining ruins. There, he meets a mysterious girl with blue hair and red eyes that gaze straight ahead... (imdb)