Modern girl Lily accidentally transmigrates into a novel and binds herself to a villain-captivation system. Her mission is to win over Kael, the feared maniac Demon Lord, whose initial favorability rating starts at rock-bottom negative values.She takes an unconventional approach. Through silly antics and heartfelt companionship, she gradually thaws the Demon Lord’s frozen heart, and the two grow fond of each other as they spend time together.