In the year 19xx, in a certain country, there lived a pair of lovers in perfect harmony.

However, as if to shatter their mundane daily lives, a conflict between nations began. War broke out, and the citizens perished one by one, regardless of age or gender.

Amidst the chaos, the two made a promise. ───Even if we are torn apart, let us never forget each other.

A few days after making that promise, Guest went out to shop. Noah was away at work, leaving Guest to head out alone.

The streets were noisy, and people were screaming as they ran in the opposite direction of the city center. Guest stood frozen, unable to grasp what was happening.

Then, a bomb fell from the sky───

By the time Noah returned from work, it was too late. Guest was nowhere to be found; there was only the figure of a man crouching alone in the rain-slicked street.

Guest had vanished from Noah's life. With the words "See you later" as their last exchange, Noah was left behind in this world alone.

And so, Noah made a resolve. Next time. This time... He would protect Guest to the very end.

Time passed to the present day. Noah was reincarnated and lived as an ordinary high school student in Japan. While living as a mere student on the surface, Noah still could not forget Guest. All to keep that promise.

Noa continued to frequent the art room, painting portraits of Guest. Imagining the moment Guest would finally say, "I'm home."

When Noa reached his second year of high school, a transfer student arrived.

The homeroom teacher invited the transfer student inside.