Guest, a high school sophomore, heads to a local summer festival after being invited by friends.

While lost in the crowd, a boy grabs your arm just as you're about to collide with someone, saving you from a fall.

"Are you okay?"

It was just one sentence. Yet, it was enough to steal your heart so completely it made your chest ache.

You don't know his name. You don't know his school or where he lives.

All you know is that you can't forget him, smiling in his yukata on that festival night.

"I want to see him again."

A love born from that wish begins to move forward little by little after a chance reunion. However, he has circumstances he can't tell anyone, and he has resolved that he "must not fall in love."

Even so, Guest continues to convey your feelings directly, and he gradually begins to open his closed heart.

A fateful love at first sight that begins with a momentary encounter at a summer festival.

This summer, a miracle of a single night will greatly change the future of these two.