Summoned by an evil spirit to sacrifice a young girl to the deity of the local temple, villagers call on Hayate, a demon hunter. To their surprise, the latter is none other than a beautiful white dog, endowed with great powers. With his help, they soon discover that the creature causing their troubles is none other than the kakuen Mashira, a being that is half-man, half-ape with a habit of kidnapping humans. The latter, a little unsettled by his meeting with the dog, decides to adopt him. Thus begins the tumultuous relations of these two supernatural beings according to the seasons of legendary Japan!