Before gaining notoriety as the fearsome 'Reaper' of the Commission of Counter Ghoul, a young Kishou Arima is tasked with investigating a string of ghoul-induced murders while undercover at a high school. Initially a solitary endeavor, Arima's plans take a sharp turn when he crosses paths with his rebellious classmate Taishi Fura. Witnessing the tragic demise of his closest friend at the hands of the enigmatic ghoul 'Lantern,' Fura finds himself on the brink of a similar fate until Arima intervenes in the nick of time. This harrowing encounter opens Fura's eyes to the world of ghoul investigations, prompting him to align forces with his unlikely ally and schoolmate to pursue justice against Lantern, setting the stage for a thrilling partnership.