The Patan High School Project reunites the two. Under the Summer Triangle, first love emerges once more as Do-ha reveals his heart to Ha-gyeong.

As secrets unfold, past grievances reach a breaking point. Do-ha and Ha-gyeong begin a long and arduous battle over her beloved Peanut House.

Ha-gyeong and Do-ha settle into a new living situation and continue working on the Patan High project. But their mutual rival Nam-jin causes trouble.