Main Cast:

Yuuichi: A young man in his early 20's. Studying at college and teaching gave him satisfaction, until long-time dog friend Kotarou came to him for assistance. He appears to be a happy young man, but after many years of living in negative environments, he is cold inside and cynical about many aspects of life, including love. He constantly gets teased by Risa and Nadeshiko about this, who can see through his lies.

Kotarou: A police/hunting dog with a high pedigree and owned by Nadeshiko. She has below-average intelligence and gets offended easily, but knows her right's from wrongs. She goes running to Yuuichi when this current problem arises.

Mikan: A rare breed of dog, she is training to become a therapy dog after what happened to her last year. She is very dedicated to her owner and master, Yuuichi, and runs away to help him.

Silviana: A very rare breed of dog but not very intelligent. She currently participates in dog shows to own money for her owner, Risa, but enjoys company more than anything and agrees to assist Mikan on her quest to help Yuuichi and Kotarou.

Kaie: Another police dog with a very high pedigree, and owned by Seika. He assists Kotarou and Yuuichi with the current issue at hand. He values Kotarou as a good friend, but constantly gets into fights with her due to his extensive knowledge and training.

Kuu: A cat that has superb intelligence and can even read philosophy and understand it. She is very cunning and quick, and is quick to assist Kotarou and Yuuichi with the current case, offering insight when needed, although she is quick to disappear into the shadows once more.

Minor Cast:

Nadeshiko: A pet store owner and owner/mother to Kotarou. She is very small in size and is often mistaken as a middle-schooler, despite being in her late 30's.

Risa: A high-school student and owner of Silviana. She is a very dedicated young girl, and will stop at nothing to accomplish her goals. She seems to have some connection to the perpetrator of this case.

Kana: Kuu's owner and in junior school. She is very easy-going and happy, and loves the snacks brought by Yuuichi and Risa. She seems to know something about the current case and the perpetrator behind it.