Swim in the Cherry

During his innocent and naive high school days, Suyeong had the worst first kiss with his first love, Chaeri. Before they can clear up the misunderstanding, Chaeri transfers schools, leaving Suyeong with an unresolved first love. Years later, after his military service, Suyeong attends a welcome party and runs into Chaeri, who has transferred as a new student to his school. He is swayed by her mysterious approach and ends up having an impulsive first experience.

"What if I gave you a chance to make it up to me?" "You started it first."

(Source: Lezhin Entertainment, translated)