He is red-brown and white Great Dane with black splotches around his eyes.
He is very loyal to Sanada Nyudounsai and begins to shed tears over his Lord when he gets carried away for treatment.
He sees Kawasemi return to say that assassins from Kurohabaki Masamune's pack. Follows him to confront the clan saying they aren't interested in joining.
Tsubakuro, Kawasemi and Unsai save Tesshin from Masamune Kurohabaki's pack. After they've escaped Tesshin tries to convince them to help Unsai refuses and the great dane leaves with his leader. Kurohabaki Masamune injures him later during the last battle.
Tsubakuro has returned to Nagano with other the Sanada ninja dogs. Reika and the puppies enter into their territory to tell them that Ou was attacked Monsoon when they agree to help. Sometime later, a flood causes a wounded Ken to be washed into a river and the Ou army go to the location to find and save him. They each keep a watchful eye on the raging river, as Kawasemi dives in to find him. After Ken is saved, Tsubakuro follows the others in the battle against Monsoon. He watches Lord Unsai get injured by the bears, when the enemy flees and humans arrive. Unsai collapses from his wounds and Tsubakuro watches with others and with tears in his eyes begging for his Lord not to die as he's carried away for treatment. Tsubakuro follows Kawasemi and Pet Dog Squad to finish off the bears this time with the help of Hidetoshi and the hunters all the bears are defeated. Tsubakuro and Kawasemi begin to notice a helicopter knowing Monsoon won't come back as along as humans are around. He witnesses Akame losing consciousness due to his injures but thanks to Daisuke and Hidetoshi, he is quickly revived and watches as the kishu is taken away for treatment.
With Gin's return he tells them the passing of their friends they all sleep together for the night. When morning comes Tsubakuro hears Kyoshiro chew Orion out for sending his friends away and then watches the fight by Orion and Kyoshiro even though the kishu lost. He saw Orion crying in tears saying that he stayed behind for the sake of everyone because the Ohu Army needs a true leader. He and the others look for Jerome and Orion when they fall out the cliff. Then, they find Jerome and Orion safe and sound near the river. After Orion's returning visit from Akame and the others, he hears that everyone is doing well. Tsubakuro goes with everyone to search for the lost sickle but after days of searching it's no where to be found. With Kyoshiro thinking that Orion isn't leader material anymore they all choose Cross to be the new boss with Kuro agreeing and when Orion returns. He hears Orion say that he is going to learn some new secret ninja techniques he picked up from Akame. Believing in the young pup he follows the others to watch Orion. Seeing the young pup's skills Tsubakuro and the others want to try too but when he takes a swing but he doesn't do the same as Orion. He hears from Orion what he learned in a day took Akame two years to learn as the training continues he becomes impressed with Orion's progressed and gets encouraged to keep training. Then, he hears that Rigel and Rocket have returned but bring a bear cub and charges at it with the others when Kyoshiro goes to attack the cub he becomes astonished that Rigel flipped the kishu over with ease after Rigel explains everything Kawasemi becomes surprised that the bear cub can speak dog and that Sirius wants them to raise Chibi until he becomes an adult. Tsubakuro watches Rigel and Rocket convince Orion not to kill Chibi. Then, hears Orion talk disrespectfully towards his comrades. When he hears that Orion is trying to protect everyone in Ohu. He also sees Orion pointing his bamboo stick at Kurotora convincing the pup to attack him but is stopped by Jerome and watches in horror as Orion almost attacks the shepard. He watches Kyoshiro give Orion a beat crying in tears but soon the tears turn into laughter as everyone runs back up the hill.
- Some fans believe Tsubakuro to be a Great Dane mix