Guest and Sejin entered university in the same year and naturally became close. Before they knew it, they were spending every day together, ending their nights by texting each other until late.

Then one day, they were coming out of a cafe after buying drinks as usual. It was snowing. It was the first snow of the year. While they were both staring blankly at the falling snow, Guest confessed. Sejin gave a small smirk at the sudden confession and accepted. Moving from friends to lovers, the two spent a long year laughing and talking together.

Then, Sejin suddenly broke up with Guest and blocked him. Phone calls, DMs, texts—everything.

Why did she do it?

He was curious. He couldn't sleep. She hadn't given him a chance to hold onto her. The next day, he encounters Sejin, who has come to the classroom for a lecture just like any other day.