Tanzaburō Tōjima is a 40-year-old man who has clung to a lifelong childhood dream of becoming a Kamen Rider. This intense dedication drove him to undertake strenuous physical training regimens in the mountains, preparing himself to the theoretical point of being able to confront a bear, a lifestyle financed through part-time work. Faced with the reality of dying alone, he once liquidated his prized collection of valuable Kamen Rider merchandise to save it from becoming trash. His circumstances shift during a robbery at a summer festival, where he encounters criminals impersonating the organization Shocker. Seizing the moment, he buys a cheap, child-sized Kamen Rider Ichigo mask from a stall and intervenes to confront the evil, effectively assuming the mantle of Kamen Rider. This vigilante act, however, makes him a subject of online ridicule. The encounter with the "Fake Shocker" acts as a catalyst, pulling him back into his dream with renewed purpose. He begins to investigate the criminal group, and the situation escalates dramatically when these investigations uncover that the actual, real Shocker organization exists, complete with authentic Combatmen and mutant Kaijin. Tōjima and his allies consequently find themselves targeted by Shocker assassins intent on eliminating those who discovered their secret. His fierce physical conditioning, honed over a lifetime, enables him to fight on equal terms with enhanced opponents like a real Shocker Combatman. Demonstrated abilities include martial prowess sufficient to wrestle a bear, gouge its eye with an elbow, and unleash a powerful "Rider Kick" capable of knocking out a convenience store robber in a single strike. His primary tool is the plastic Kamen Rider Ichigo mask, which he uses to conceal his identity and enact his symbolic transformation. He maintains a familial relationship with his father, Gonzaburō Tōjima, and a younger half-brother, Yumezaburō Tōjima. His allies include other individuals who share his passion for Kamen Rider and have similarly trained to embody their own heroic ideals, such as Yuriko Okada, who aspires to be Electro-Wave Human Tackle.