A burnt-out Grim Reaper forced to mentor a girl who actually believes in him is the opposite of what he wants. The show plays that friction for genuine laughs, real stakes, and the kind of character growth that sneaks up on you. Yashiro's a scumbag who keeps trying to quit being a mentor, but every case pulls him deeper into something that matters. The sci-fi Tokyo mafia setup is window dressing for a story about two people learning to save each other instead of themselves.

In an alternate mid-21st century Tokyo, members of the mafia use ether augmentation surgery to transform into powerful Demon Lords. Bounty hunters known as Braves, who wield ether powers of their own, are the ones called in to bring them down. Yashiro, nicknamed the Grim Reaper, calls himself a first-rate Brave, yet he can barely pay his bills and mostly wants pizza, beer and card games. After he helps Aki Jogamine, a student at Shibuya's Brave Academy, she pleads with him to rescue her friend Saera Kashiwagi Pendragon from a Dark Lord, and he reluctantly goes along. Afterward Aki, Saera and their friend Yukine Indou insist on becoming his apprentices and offer him a large sum to tutor them. Yashiro accepts for the money, then keeps trying to convince the trio that bounty hunting is too dangerous for them. The result is an action comedy with fantasy and sci-fi elements, built around a scruffy mentor and his eager students.