Tetsu and Masari have been best buds since they were in 2nd grade and are feared and well respected amongst the gangs in their neighborhood. One day, Masari was riding his bike as usual when he got into a streetfight with some thugs and had an accident. Tetsu rushed to the hospital only to be informed that his friend is unconscious, and that he only has 20% chance of survival. Tetsu is devastated, but then he hears Masari. He turns around and sees... no-one? Following instructions to look down he is shocked to see a talking Dog.
The dog tries to explain that Masari's accident was a mistake - the dog was supposed to die. A god told him he was trying to fix the mistake, but when Masari yelled after him the god was gone, and he was stuck in the dog's body. Tetsu finds this hard to believe, but the dog knows all about him, and sits and talks in the same manner that Masari does. As he finally starts to believe him, they realise that Tetsu is the only one who can actually hear Masari - everyone else just hears the dog's bark. Now Masari wants Tetsu to find the thugs responsible for his accident, and that is where this story begins. Will Masari be able to become human again?