"Tiger & Bunny" is set in the fictional city of Sternbild, where individuals with superpowers, known as NEXT, work as corporate-sponsored superheroes. These heroes, called "Hero TV," compete to earn points by capturing criminals and saving civilians, with their actions broadcast on a popular reality show. The story centers on veteran hero Kotetsu T. Kaburagi, also known as Wild Tiger, whose old-fashioned sense of justice often clashes with the corporate-driven nature of heroism. His life takes a turn when he is paired with Barnaby Brooks Jr., a young, calculating hero with a mysterious past and a personal vendetta.

The two heroes, despite their contrasting personalities and approaches, are forced to work together as a duo. Kotetsu struggles with his declining powers and the pressure to support his family, while Barnaby seeks to uncover the truth behind his parents' murder, which is tied to the origins of NEXT abilities. As they investigate a series of criminal incidents involving rogue NEXT, they uncover a larger conspiracy involving the organization behind Hero TV and the true nature of their powers.

The series explores themes of heroism, identity, and the commercialization of justice, with a focus on the evolving relationship between Kotetsu and Barnaby. Supporting characters include other heroes like Blue Rose, Rock Bison, and Fire Emblem, each with their own motivations and struggles. The narrative balances action-packed heroics with character-driven drama, culminating in a climactic confrontation that challenges the heroes' ideals and forces them to confront their personal and professional conflicts.