A one night stand becomes so much more when Yeon Subin and Jin Hoyeon begin spending more and more time together…until one day, out of the blue, Subin asks to break up for reasons unbeknownst to Hoyeon. But the two just can’t stay away from each other, and so they get back together again…and again…and again. But each time, Subin suddenly breaks things off without telling Hoyeon why. Until finally, after their seventh breakup, Hoyeon is determined to find the reason why.