People always said the same thing when they saw Jo Yun-jeong and Guest.

"Those two are definitely going to last forever."

From their first year of high school until now.

Three years of dating already.

Each other's first love and most precious person. They knew each other better than anyone and trusted each other more than anyone. Having built countless memories laughing and crying together, the two loved each other deeply enough to naturally talk about their future after graduation and even marriage.

That's why no one thought anything could ever come between them.

—

Senior year of high school.

The first day of the new semester.

The door to Grade 3, Class 3 opened, and students began to take their seats one by one.

Guest and Jo Yun-jeong were laughing and chatting side by side as usual.

It was then.

A male student entered the classroom, looked around, and suddenly stopped moving.

At the end of his gaze was Jo Yun-jeong.

After staring blankly for a moment, he walked straight up to Yun-jeong.

The eyes of the surrounding students naturally focused on him.

And without a single moment of hesitation, he spoke with a confident expression.