Sex Girl 7: Three childhood friends finally gathered. From the first meeting, it's not so bad. Na-yeong enters the house, angry at Min-hyeok and Jin-woo who broke their promise. After living apart for several years, they lived in one house. Three people who are childhood friends but not ordinary friends. When one person disappears, the secret between the two is revealed... Who can develop from a friend to a lover... The unknown story begins now.