Jiyeon, Suzy, Ji Eun, Sohee and Hyerim are best friends. Despite their age difference, they get along wonderfully. Jiyeon, Suzy and Ji Eun  are first years at Seoul University while Sohee and Hyerim are second years at the same university. The five share a two storey apartment in downtown Seoul. When five guys move into the house next door, things start to get crazy. The two groups are at constant loggerheads with each other. And it doesn't help that they are attending the same university. The girls find that they cannot have a moment of peace ever since the guys moved in. Will the girls ever find peace and love? Will the guys win their hearts?

Couples: Suzy/Myungsoo, Sohee/Taemin, Hyerim/Kyuhyun, IU/Wooyoung and Jiyeon/JB