Ha-gyeong's first love, Do-ha, reappears in the midst of summer. A property sale goes awry, and old wounds reopen as their summer ignites once more.

Back from a 2-year hiatus, Do-ha refuses defeat and attempts to win back Ha-gyeong's heart. Old memories from a summer past unlock as the rain pours.

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.