Its about Kim Taexi who is the 14th member of seventeen and is the only girl in the group. She became a trainee since she was 7 yrs old but her connection with boys goes way back. FYI here seventeen and taexi knew each other since the beginning cause they all lived together in a housing and all of their parents are best friends and are the part of navy due to which they couldn't spend time with their children and taexi was basically raised by seventeen and let's see how things unfolds as they all become the part of same group.