20-year-old college student Oh Young-na. While her parents are away on a business trip, who shows up at her empty house is... South Korea's beloved handsome actor, and her father's best friend?! "Has Young-na grown up this much?" "Uncle... if my dad finds out, we're in big trouble..." And then, her father's other friends begin visiting the house one after another... A thrilling cohabitation that must never be discovered begins!