He is nicknamed "Shōji the Mamushi" for his tenacious spirit of hunting down criminals.
3 years ago, he and his partner, Tanuma, were in the Southern Alps on a mission to capture a criminal. There they found an abandoned kennel. As they inspect it inside, they saw Hōgen and Genba standing on the pile of dead bodies eating a dead human. Then, the hungry dogs attacked the policemen. Though Shōji only lost his left eye, Tanuma was mercilessly mauled to death by Hōgen and Genba. Fuelled with hatred, Shōji swore to hunt down and kill Hōgen and Genba for the loss of Tanuma.
Shōji Sudō was first introduced in the story when Daisuke and Hidetoshi were having a discussion about the dogs during the meeting at the cabin. Daisuke and Hidetoshi realized who Weed was really dealing with when Shōji showed them the photo of Hōgen and Genba (that time, Daisuke saw the Great Danes earlier from the helicopter above the dogs). Shōji, Daisuke and Hidetoshi went to discuss with the town council who came up with the solution to deal with the wild dog problem - bomb Gajō. However, the plan did not work when even though the bombing at Gajō caused a number of casualties for the wild dogs, it turned out that Hōgen was still alive as he ran away and hid behind the tree far away from the explosion. Dissatisfied with the council, Shōji went off alone to hunt down Hōgen all by himself. On the way, he encountered the mastiff Moss who had been lying in the snow keeping wounded Tesshin warm. When Moss got apprehensive at his presence, Shōji prepared to shoot them with his rifle in case both dogs are from Hōgen's pack. Fortunately, Shōji heard the other dogs' howls from nearby which stopped him from shooting both just in time.
In the end, he finally found Hōgen, heavily wounded and tired from the battle with Weed. Without an ounce of mercy for the defeated dog, Shōji shoots Hōgen straight through the head several times with his rifle and avenges his friend.