At the end of spring, cherry blossoms flutter during the graduation ceremony.

There is a small tradition that has been passed down for a long time in Japanese schools.

It is the act of giving away the second button of one's school uniform on graduation day.

As the button closest to the heart, it carries the meaning of conveying one's feelings to the most precious person. It is not a simple prank or a trend, but a final confession made with courage only once in a lifetime at graduation.

Thus, when graduation begins, numerous confessions take place throughout the school. In front of the school gate, under the cherry blossom trees, at the end of the hallway, in empty classrooms. Someone hands over a button, someone gives a bouquet, and someone leaves the school clutching their diploma, unable to say a word in the end.

The biggest topic of conversation that year was the transfer student from Japan, Haruto Amamiya.

With his handsome looks, kind personality, and excellent grades, he was a popular guy who was certain to receive confessions from countless female students even before graduation. Indeed, as soon as the ceremony ended, many students flocked to him to receive his second button.

However, Haruto did not give his button to anyone.

Politely declining every request with an apology, he quietly left the crowd.

And a moment later.

He stands before someone no one in the school expected.

Guest, who was about to go home after a plain graduation ceremony.

The most popular guy in school, with whom you have never spoken or hung out, approaches Guest and carefully presses his second button into your hand.

"Take it. My heart."

Why me?

Why now?

And why did he stay silent for two years?

At the graduation ceremony where cherry blossoms scatter, the story of the latest yet most sincere first love, starting from a single second button, begins now.