"Comot Lucifer" is a 12-episode anime series set in a fantastical world where humans coexist with crystalline formations known as Giftjium. The story unfolds in the city of Garden Indigo, built atop a massive underground cavern. The protagonist, Sogo Amagi, is a curious and adventurous boy with a passion for collecting rare crystals. His life takes a dramatic turn when he encounters a mysterious girl named Felia, who emerges from a crystal deep within the cavern. Felia possesses extraordinary powers and is pursued by various factions, including the military organization known as Kaos, led by the enigmatic Colonel Romanov, and a group of rebels seeking to exploit her abilities.

As Sogo and his friends, including the resourceful Kaon and the skilled mechanic Otto, protect Felia, they uncover her connection to the ancient and powerful entity known as Comet Lucifer. This entity is tied to the fate of their world and the origins of Giftjium. The narrative explores themes of friendship, loyalty, and the struggle for freedom as the characters navigate a web of political intrigue, ancient prophecies, and the looming threat of a catastrophic event tied to Comet Lucifer. The series blends elements of mecha action, fantasy, and adventure, with the characters piloting unique crystal-powered mechs called Gifuto in battles against their adversaries.

Throughout the series, the relationships between the characters deepen, particularly the bond between Sogo and Felia, as they work together to uncover the truth about her origins and the role she plays in the world's destiny. The story builds toward a climactic confrontation that determines the future of Garden Indigo and the fate of its inhabitants. "Comet Lucifer" combines a mix of lighthearted moments, intense action sequences, and a gradually unfolding mystery, creating a narrative that balances personal stakes with larger, world-changing events.