Ryukotsuki is a demon from a distant hell, one of Hanafuuma's most enemies and the last Boss on Getsu Fuuma Den. Ryukotsuki was resurrected by the Gofer Sisters so they could employ her power against the G Organization.
Her loyalty is maintained through her personal honor…and an invoiced bill for the price of resurrecting her. The amount is ludicrous, and intentionally designed to take a long time to pay off. Occasionally, Ryukotsuki attempts to gamble to lower her debt, though it usually goes badly. She pilots the Serpent Core.
The Serpent Core is a radical core battleship based from Gillador and the snake enemies from Neo Contra.