Together with Tesshin, they're the last Kōga dogs.
He is red and white Kōga with mohawk on his head.
He is extremely loyal to Tesshin, when under extreme anger he can be doubtful about the intentions of others like Sirius. He also saw Tsukikage as a close friend.
In the Battle for Gajō, when Buruge (who had allied with the Ōu soldiers) had deceived Hōgen and called for more reinforcements, only two Kōga dogs had came in. While the other Kōga dog left to alert Kurotora, Kaito, Batto and other dogs, Toshimitsu stayed with Buruge to wait for others in order to throw Hōgen off the cliff. However, this plan did not work when Hōgen realized that he threw the attacking Buruge off the cliff. Then Toshimitsu saw this situation did not do any good and howled for more reinforcements. Before the reinforcements came, Toshimitsu tried to take Hōgen down by himself but fails as Hōgen had pushed him down. However, it turned out that Toshimitsu, Buruge, Batto, Kaito, Kurotora and others had survived the fall and they were present at the final battle of Weed and Hōgen.
Tesshin sent out two Kōga dogs Toshimitsu and Tsukikage to find more reinforcements while the Ōu Soldiers were at Hokkaidō. On their way, while Tsukikage tried to fend off several soldiers who worked under Victor, Toshimitsu found Kyōshirō, Teru and the puppy ninjas. When Tsukikage was about to be killed by the Russian dog soldiers, Toshimitsu, Kyōshirō, Teru and others managed to arrive on time and drove the Russian dog soldiers away.
Later, they came to help Orion and his friends fight against Mateus's troops. Ninja Dogs went to Orion by, but vowed not to acquire their home back. Later Toshimitsu and Tsukikage to Gennai Ogasawara losing Kenshin Nokizaru down the tree and subsequently to release Shiro by Masamune Kurohabaki.
Toshimitsu is among the group of ninja dogs who are given orders to lead the females and children away from the battle when Monsoon and his kin attack Ōu. When Akame is far enough away, Toshimitsu, Tsukikage and the Kōga Elder turn back and attack Monsoon to buy the remaining dogs some time. All three are critically injured and placed in a makeshift prison.
Many days later, Toshimitsu and the rest of the dogs are rescued by Mole and his group. Barely able to walk due to injuries and being cramped in the prison for so long. Shortly after, Toshimitsu and other Ou army are resting in the grass during a storm. After The Koga Elder's death, Toshimitsu and Tsukikage reminded Tesshin that they were ordered to remain in that place, but Tesshin says that as long as they are here, they can not kill Monsoon and will not be safe. When Monsoon and the bears are gone he hears from Sirius that they should come up with a new plan. But just like Orion, Toshimitsu thought there's no reasoning with that monster. He was so angry that he even thought that Sirius would consider siding with the enemy until he was calmed down by Tesshin. He was taken into treatment with the other injured soldiers.