"My student from ten years ago has returned as a grown man."
A secret and sweet real-life romance between veteran academy instructor Seo Hye-jin and her flirty student Lee Joon-ho, who returns after 10 years and stirs her heart.
Some instructors leave the academy, and some request to meet Hyun-tak to talk about their plans. Seung-hui reaches out to Min-jin and asks her to be her spy in Choi-sun and betray Hye-jin. After discovering what Seung-hui did, Hye-jin decides to face the one behind all the schemes around her. As she goes through the struggles, she thinks about what she really wants to do.