Tagawa Kyo could just die from overwork, but instead he's accidentally summoned to another world, still dying in the real one, and immediately gets into trouble.

The world immersed in apparent peace will soon face war. The dragon princess aims to get rid of humans and in exchange for sparing Kyo's life, she becomes her spy.

His lonely mission very quickly ceases to be a one-man mission. He is joined by the dragon prince, who does not intend to reveal the truth about his position and the reason behind Kyo's arrival.

Their journey has one goal: to protect peace at all costs and bring down the wall dividing the two races.