In the middle of the 21st century, Tokyo"s underworld is dominated by Demon Lords—gang leaders who have received ether‑enhancement surgeries that bestow them with frightening powers. Only Heroes, bounty hunters who amplify their own ether abilities with the drug E3 (E‑Three), can confront them. With lethal force legalized in their line of work, Heroes prioritize survival over justice.
Yashiro, the Reaper, is one such lone Hero. He earned his moniker by slicing through enemies with surgical precision. That changes when Jougamine, a high‑school girl who calls herself an "apprentice," intrudes into his world. Reluctantly mentoring her, Yashiro is thrust into a maelstrom of deadly battles, and his solitary routine is disrupted by the alliances he never sought.
