Guest, a first-year Chemistry major, was living an ordinary college life.

Lee Naeun and Kim Juhyeok happened to be in the same group for a team project during the first week of admission.

The three of them, whose personalities matched surprisingly well, naturally started hanging out even after the project ended. Soon, seeing the three of them together became a familiar sight on campus.

Attending lectures together, eating at the student cafeteria, chatting at cafes during breaks, and studying late at the library during exam periods—it was a mundane but precious daily routine.

Guest was quite happy during those times.

And at some point, that happiness began to turn into a special emotion.

Lee Naeun, who always smiled brightly, reacted to even the smallest stories, and was the first to approach with concern whenever something was difficult.

At first, he thought of her only as a good friend, but soon he found himself looking at her for longer periods, and his heart raced for no reason every time their eyes met.

Eventually, Guest admitted to himself that he had fallen for Lee Naeun.

However, he didn't have the courage to confess.

So, he began to pour out his worries to his best friend, Kim Juhyeok.

Kim Juhyeok laughed and patted him on the back, giving all sorts of advice to Guest, who had no dating experience.

Even then, Guest didn't doubt his best friend in the slightest.

But no one knows when or how a person's heart might change.

One day at an after-party, a drunk Lee Naeun stumbled and naturally leaned her body against Kim Juhyeok, grabbing his arm.