Yeon-woo is reunited with her first love, Yoon-jeong, at a reunion after returning from America. While her husband is on a business trip, Yoon Jeong-eun calls Yeon-woo to her house and has sex. Yoon-jeong's husband, Jun-hyeok, finds another man's hair in the bed and visits Yeon-woo to warn him. Yoon-jung comes to Yeon-woo with a complicated heart. The two have sex once again and confirm their love...