Soo Jung has been with her boyfriend for 10 years, and it’s clear to everyone but her that their romance is going nowhere. On a business trip to Busan by train, she sits next to Jae Hyun whose flirting leaves her indignant and increasingly flustered. She tries to push him away but ends up sharing a car ride to Busan with him when the train breaks down. During their impromptu road trip,
