48-year-old detective Sudo Tomozo, who is feared as the assistant inspector from hell, was with the Tokyo Metropolitan Police Department’s First Investigative Division until he sustained head injuries in a case. He was discarded by the First Investigative Division and assigned to a department for deadwood, the General Affairs Department’s Animal Unit which provides shelter and care for the pets of detained suspects for a specified period of time. However, these “pets” do not necessarily mean the popular kinds such as cats and dogs. Rather, those such as snakes, tortoises, owls and even penguins!? Its only police officer is a 22-year-old rookie, Usuki Keiko who is a graduate of veterinary medicine and crazy about animals. Besides Tamaru Hiroko the clerk and Mikasa Yayoi the receptionist, is former detective Nidegawa Akiyoshi who comes to chat with Yayoi. Sudo is disappointed to have been given the transfer notice from the director of the First Investigative Division Kito Tsutomu. Sudo’s former partner Ishimatsu Kazuo is elated that he has returned to work so Sudo tells him about his transfer to the General Affairs Department. At that moment, Hiroko urges him to go to the scene of a hostage taking incident. When he heads over as he was told, detectives Nitto Hajime, Ishimatsu and Sakurai Kaoru, his former colleagues from the First Investigative Division, are there and calling out to the hostage taker who has barricaded himself in an apartment to surrender. When Nitto notices Sudo, he points him to the empty land near the apartment as the scene he should be taking care of. Sudo looks over and sees Keiko wearing coveralls and a gas mask, peering into a drain. She has come here to save a cat stuck in the drain. Sudo is surprised that the police is mobilised to save a cat and Keiko responds that this is their job. Sudo takes a good look around when he returns to the Animal Unit. There are dogs and cats in the space. Keiko is an expert in handling animals and takes care of them. Then Ishimatsu comes over with a request to provide shelter for the pet of a suspect in an abandoned dead body case. After hearing a general outline of the case, Sudo and Keiko go to the high-rise apartment building where the suspect lives. There are big bird cages in the apartment with close to 20 birds in each cage. Sudo looks around the place and feels something is strange … … Sudo gets exasperated with Keiko who loves animals more than humans and rushes headlong in her own direction. However, the appearance of the pets left at the crime scenes somehow helps her to solve crimes. She makes astonishing inferences from her immense knowledge and sharp observation skills. Sudo gradually gains respect for her and they partner to solve cases one after another.