あらすじ
After their parents' sudden passing, Gyeon-U finds himself in the role of caregiver to his younger sister, who harbors a startling secret—she's the Demon Lord with plans for world domination! Undeterred, Gyeon-U is committed to nurturing his sister with love and guidance. Join them in this unique tale as they navigate everyday life amid their extraordinary circumstances.
あらすじはAniListより（英語）。
