After the hybrid bear crisis, Jerome and Lydia got 6 pups: four males and two females. One of them was Tonov. He and his siblings were born in autumn in Futago Pass, three days after the birth of Weed's and Koyuki's pups Bellatrix, Orion, Rigel and Sirius.
When a volcano erupts in Ōu, the dogs are forced to flee. Tonov is too small to run fast enough and is carried by the Ōu army to safety but they pass out from the smoke and ash in the air. Jinemon Kurohabaki finds them and takes them to an abandoned mine where he locks them up. Tonov and the others are later released by Daisuke who acquires the key from Jinemon.
A few months have passed in Ōu when the son of Akakabuto, Monsoon, attacks they Ōu Army intending to kill them all and take back his fathers land. Tonov is with his mother and siblings when they are suddenly attacked by red backed bears and are forced to flee. His brother, Lenov, is crushed and killed by one of the bears along with Akira and Tetsuo who try to help their brother. Lydia is badly injured as well and carried to the top of a hill where Gin is calling for everyone to gather. Tonov and his surviving siblings cry over the body of their mother as she dies from her injuries. When his father, Jerome tries to make a suicide attack on Monsoon, Tonov joins in but is stopped by Kurotora and Rocket. Ultimately, Gin orders the females and pups to be taken away from the battlegrounds to safety.
Tonov is taken to safety by Reika whilst Sunny and Maru are led to safety by Cross. Despite being under protection, Tonov is distant from Reika and Hiro's children. He is quiet and sleeps away from them when they stop for a rest.