Mitsumori Touka, a high school student known as a background character, is summoned to another world with his classmates. While his classmates receive A-rank and S-rank hero statuses, Touka is the lowest-ranked E-rank. His acquired skill is considered "trash" in this world: "Wait for me to return alive—then you'll resign yourself to fate." The story of an E-rank hero, initially content with being a background character, who rises to become the absolute strongest begins!