A Hellhound who was abandoned by his family for his small size who goes by the name of Yale Twotails, gets chosen by the Hellhound Lord to live with her after seeing his state. Over the years, he has deemed himself worthy to her, hence, she sends him out to the Overworld, Earth, on an important mission to collect valuble data on what the humans are up to. As soon as he reaches there, he instantly gets mistaken for a normal DOG by a human named Kin Tsune! She finds him shivering under a bench in a park one day and the next thing Yale knows, he's stuck as a pet in the mortal's house!...All though, he doesn't really mind the dog food there...