Hannune Banhada!

Kang Han-Se and Ban Ha-Da have known each other ever since their childhood. They are close enough to sleep in the same room still at their current age.

"Three men for you," Kang Han-Se's mother tells Ban, Ha-Da on the day of graduation. As soon as Ban, Ha-Da starts her life as a high school student, her love life starts.

(Source: Korean publisher, translated)