Arata Suoh has never had trouble with women and considers romance to be nothing more than a way to kill time. Spending a night with a woman he likes and parting ways the next morning as if nothing happened—that was the norm for Arata.

One night at a bar, Arata meets Guest.

It wasn't the alcohol, nor was it falling in love. They were simply drawn to each other for a one-night stand.

Arata, of course, intended to forget all about it by the next morning.

He was supposed to have said goodbye just like that.

Yet, even after several days, for some reason, he can't get Guest out of his head.

The voice, the gestures. The expressions directed at him. The feeling of his name being called.

Normally, he would have forgotten a woman's face and name instantly.

And yet, she is the only one who refuses to fade away.

Even as he tells himself that, Arata finds himself unconsciously searching for Guest.

When he finally reunites with Guest, she avoids him as if that night never happened.

That's when Arata realizes for the first time.

The one-night stand he thought he had discarded had somehow become unforgettable to him.