After his girlfriend Yuuko breaks up with him, Miyu Samura's luck hits rock bottom. But several months later, she reappears and hands Miyu a toy poodle that she supposedly cannot look after. Miyu knows nothing about dogs, and the puppy's unruly behavior puts him at risk of being evicted from his own home. When Miyu decides to take the puppy for a walk, he has a chance encounter with professional dog trainer Shinichirou Niwa and Niwa's well-behaved standard poodle, Ourson. In just a matter of minutes, Niwa not only corrects the attitude of Miyu's dog, but also gives Miyu himself stern advice on how to treat his pet properly. Amazed by Niwa's techniques, Miyu decides to quit his job in order to become the trainer's assistant; however, Niwa is not as skillful in dealing with humans as he is with their canine companions. Even so, Miyu refuses to give up on Niwa and his failing business.