Choi Hong is a Korean student studying in Japan. She meets Aoki Jungo, and they fall in love with each other. But, they break up due to different thoughts about love and practical problems. Five years later, Hong and Jungo meet in Korea.
Hong heads to Japan to escape her life in Korea. While there, she crosses paths with a guy who makes her question her disbelief in everlasting love. Fast forward a few years, she’s back in Korea alone. Now, work is the only thing keeping her going, until one day, things start to change again.
Jungo is taken aback to discover that Hong will be his interpreter. Hong, equally stunned to learn who the writer is. Throughout the day, Jungo is constantly reminded of their shared past, while Hong appears less than thrilled to see him. By the end of the day, their farewell feels final, as if they may never cross paths again.
Just as Hong begins to drive away, Jungo suddenly steps in front of the car, forcing her to stop. They sit in the car, enveloped in silence, the awkwardness of years apart hanging between them. Nothing happens that night, but to Hong, what was meant to be nothing feels like something more.
After their brief encounter, Hong is constantly reminded of her time spent in Japan when she was together with Jungo. While Hong prepares for her marriage with Min Jun, she reminisces about the time when she and Jungo pictured their own marriage and also got into a big argument as they were invited to an acquaintance’s wedding.
Hong thought she had moved on from Jungo the day she grew tired of his broken promises and constant absence. Convinced that her love was a failure, she believed there were no lingering feelings left. However, her actions suggested otherwise, and Min Jun’s words became the catalyst for change. In that moment, she got up, drove off, and let her heart lead the way.
Hong's heart guides her to Jungo, but witnessing him with Kanna shatters her heart once more. The day before Jungo leaves for Japan, he visits her office and places a key chain exactly where it belongs. Later, Hong sees it and reflects on her true feelings about their love at its peak. The two eventually sit down for a long-overdue conversation, and gradually, things begin to change.