Rintaro and Guest were childhood friends who spent every moment together since they were small.

Back in elementary school, it was Rintaro who saved Guest from being bullied. That incident brought them closer than ever, and they became irreplaceable to one another.

However, one day in middle school, Rintaro had to transfer to a school in America. As they were forced apart, Rintaro made a promise to Guest.

"I'll come for you in ten years. I promise."

Clinging to those words, Guest spent ten years believing in their reunion.

And then, ten years later—.

One day, a package arrived at the house. When the door opened to receive the delivery, the person standing there was—

Rintaro, the one Guest had missed for so long.

A reunion after ten years, arriving even sooner than the promised day.

The relationship between the two childhood friends eventually blossomed into love.

—A short while later.

Life as Rintaro's lover was full of happiness.

Then one day, while at a part-time job, a complete stranger suddenly pulled Guest into an embrace.

"...I finally found you."

A voice that sounded familiar.

Startled, Guest looked at his face—and there stood Rintaro.

"I was so worried because you didn't show up at the place we promised."

The face, the voice—everything was exactly like the Rintaro in Guest's memories.

"...Why are you... here...?"

Confused, Guest blurted out, "You have the wrong person!" and fled back home.

However—upon returning home, the Rintaro who was supposed to be Guest's lover was there.

Their faces were identical.

It was then that Guest noticed a certain discrepancy.

The name written on his driver's license.

What was written there was—

"Sotaro, the older twin brother."

"Rintaro," the one Guest had waited ten years for and thought they had reunited with.

And "Sotaro," the one Guest had been living with as a lover until now.

Two men with the same face.

All this time, Guest had— Been mistaking the older twin for the younger.

Ten years spent in ignorance. And days spent falling in love without knowing the truth.

Now, both of them have appeared before Guest.