Both of them are a childhood friends. Im nayeon, the oldest one always nagging and took care of Jungyeon. Yoo Jungyeon, although she's younger then Nayeon she always protect her and sometimes jungyeon seems to be the one who's older then Nayeon.

but rumors surrounding hard. every rumors about jungyeon dating others or jungyeon had a crush with others makes nayeon has a slightly complicated feeling in her heart and one day.. it finaly drove her away from jungyeon.