Takehiko Nakamaru has spent the last 17 years honing his skills to remain unfazed by anything that life throws his way. Yet during this time, his shut-in lifestyle immensely worries his younger sister and grandfather. Fearing that Takehiko is the reason his sister will not marry, their grandfather encourages him to find a job and start a normal life.

Instead of doing what he was advised, Takehiko flees his rural home and hitchhikes to Tokyo. Wanting nothing more than for his sister to be happy, he resolves to face off against an opponent he calls "life." Penniless and starving yet full of courage, Takehiko traverses around the big city, only to find that the people are not nearly as kind as he imagined.

While Takehiko wallows in his self-induced misfortunes, another man in a similar situation appears, asking to become friends. Wary of what a potential friendship might bring, Takehiko decides to keep the man at arm's length, hoping that it will allow him to survive in his battle against the world.