Sera has never dated, but her curiosity about sex is boundless. Browsing a dating app one night, she stumbles across a shocking post: “Looking for a mistress who can tame me.” Intrigued, she digs deeper, only to discover that the man behind the post is none other than her university lecturer, Professor Baek. Now, with his secret desire exposed, Sera can’t help but begin her own exploration — into both his private world and her own awakening.