Five people are summoned to another world to battle the Mazoku who threaten that world. However, there were only supposed to be four heroes. Our protagonist, Nakajima Saito is labeled useless. Saito is an arrogant, gloomy young man who follows his own path of choice wherever he goes. He is extremely egocentric and only does something if he’s perceived something to be useful, of interest, and/or is given sufficient compensation for it. The people that summoned the heroes do not approve of him because he is too sharp. So they try to kill him.
However, the Goddess of Chaos notices that he has a unique skill and chooses him as the vessel for an ancient power. The highest form of ice magic. Because the only way to avoid death was to accept the Goddess's help, he agreed to inherit that power. But wait. Now his body had to change in order for the power to accept him. Once a man, now he turned out to be a beautiful fox girl. Or perhaps, something else?
Now that nobody can recognize him anymore, he/she has a clean slate. So will our protagonist get the carefree life she desires? Or will she have to devour everything in her path?