Yoshito Sawamura is a minor character.
He's the father of Giichirō Sawamura, Shinjirō Sawamura, Seisaburō Sawamura, and Rumi Satō, grandfather of Yūta Satō, Anju Sawamura, Tatsuya and Junya Sawamura. Also the owner of Yuki and her four pups; Jirōmaru, Tarōmaru, Saburōmaru and Koyuki.
Yoshito used to be a matagi hunter, but as he got older he became a gold seeker. When his eldest son Giichirō died in a car crash with his wife and two of their three children, his second son Shinjirō took the only surviving child Anju and trated her poorly. This made Yoshito to one night in a snow storm go to his house with his akita dog Yuki and rescue Anju.
For two years they lived happily, and Yuki got four puppies; Jirōmaru, Tarōmaru, Saburōmaru and Koyuki. He was happy to see Anju play with the pups. One day he took Yuki with him to continue to search for some gold. They found some more and hid it in a bag under a moon-crescent rock, where he already had collected a bunch. When he was on his way back, he tried to grab some herbs he knew Anju liked when he climbed on a hill, but a snake bit him and he lost his balance and fell down to his death on the rocks below. His body was found by Jirōmaru, who had been told by his mother who had manage to get back, and the mailman. After that his body was taken away and had a funeral that Shinjirō and his family, along with Rumi and Anju attended to. His youngest son was sadly out of Japan.