Kotobuki was a member of the Iga Clan.
Kotobuki is a solid red Kishu-inu. She has long eyelashes on her eyes.
She's as brave as any ninja dog, sees great potential her son Akame when he is the first one to open his eyes.
When Ryōjun, Ōzaru, Benimaru and Kuma left into the woods, Kihē ties a message on Kotobuki's neck and sent her to carry a it to the upper ninjas. Kotobuki collides Sadamitsu on her way. They discuss the message, followed by Kotobuki's return trip home. When she rests, she sees Hakutaka and surprised that the puppy already has opened his eyes.
Kotobuki is now in a small role in the story and sees him involved in the fighting, although she is said to be able to fight a ninja dog.