Comet Lucifer

The story takes place on the planet Gift, where precious crystals called Giftjium are buried in the earth. A young man named Sōgo lives in Garden Indigo, a prosperous mining town. Sougo'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...