In the scorching summer, three young people fall in love for the first time without even realizing. Yoon-ho, Jae-woon, and Seol have been good friends, being shoulders to cry on, and continue their friendship until the coming of age ceremony. However, Yoon-ho notices his heart jumping for his friend and grows his feelings without being able to tell anyone. His feelings were hiding behind the friendship all along. The comping-of-age, love story of young Joseon people starts!