As Kobayashi prepares to go for work, she opens her apartment door to see an extraordinarily terrifying sight—the head of a dragon glaring at her from across the balcony. The dragon instantly turns into a pretty, busty, and lively young lady clothed in a maid uniform and introduces herself as Tooru. The stoic programmer had seen the dragon the night before on a drunken expedition to the mountains, and because the mythological beast had nowhere else to stay, she had offered the creature a place to stay in her home. Tooru had so came to take advantage of the opportunity, eager to reciprocate her savior's goodwill by working as her personal maidservant.