Shinku Izumi is a normal boy who studies at the International School in Japan, and has a normal life everyday until he suddenly got summoned to an alternate world called Flonyard. The people there look no different from humans, except for one thing; they have ears and tails like dogs' (and other creatures that are similar, like foxes, etc). The one who summoned him is Millhiore, the Princess of the Biscotti Republic, who requested his assistance in repelling the forces that seek to invade their nation, known as the Galette Lion Army. He receives one of the pair of Sacred Swords, the Palladion, and is appointed as a Hero.

How would Sink lead his life in Biscotti, and interact with the various characters there, and would he be able to successfully defend his allies who he would later love so much?