Yūjirō lives in the village in Akita with his family. After his sister turned ill, Yūjirō's family took care of her dog Yamabuki. When Yamabuki had puppies with famous bear hound Shiro, many villagers came to visit their house and see them.
Month passed and the hunter Gohē Takeda came to take one of the puppies for training. It was a tradition and Yūjirō dared not to intervene because the old man was drunk and could get violent when angry. Yūjirō is a bit displeased when Gohē takes the white puppy which is the strongest of the litter. Worried, he asks Gohē to take care of the puppy.
Three months passed and other puppies got new owners except the small red one. Yūjirō decided that their family will keep the puppy as their pet since no one else wanted him. Yūjirō named the puppy Riki, which means "strength", hoping that the puppy will grow big and strong despite the small start.
Few months pass and Yūjirō gets a phone call: his big sister is getting better and is back home from the hospital. Big sister wants Yamabuki back so the family drives to Miyagi to give both Yamabuki and Riki to big sister: Yūjirō thinks it would be cruel to separate the mother dog and the puppy from each other. But after big sister turns out to be still weak, the family decides to keep Riki since the energetic puppy would be too much for the old big sister to take care of.
After family returns home, Riki runs away at night to seek for his mother. He returns a bit wounded and is healed. Yūjirō is confused but thinks that maybe Riki is a good fighter despite his size since he is a son of Shiro.
Yūjirō and his family aren't seen in the story much after this but it's known that Riki stayed as their pet for about 3 years and became Gohē's bear hound after this.