Fourth season of Strike the Blood.

Yuki wakes up to find herself in an unfamiliar manor, wearing a maid uniform and lying on a luxurious bed. Soon, she discovers five more girls, all dressed the same as her. This is the Ghost House, and the only way they can survive is to make it through the traps that lie in wait—deadly games full of blowguns, buzz saws, locked rooms, and weapons. It's a hopeless, terrifying situation for everyone there...well, everyone except Yuki. After all, this is her career at seventeen. Do you think that's odd? She would agree. But that's how some people are—they earn their living playing death games.

Bullied by his classmate and popular Newtube streamer Pakgo, Yoo Hobin's high school days are filled with humiliation and abuse. His troubles don't end there though; outside of school, Hobin slaves away at a part-time job to pay for his mother's hospital bills. One day, Hobin accidentally spills ramen on Pakgo's cameraman "Jiksae," tripping over a cord and disconnecting the other boy from his gaming stream. Finally fed up with his miserable lifestyle, Hobin fights back and ends up in a pathetic brawl with Jiksae. The next morning, it is revealed that the camera from Jiksae's stream had been recording the two boys' entire embarrassing fight. Moreover, the footage was accidentally uploaded to Newtube and had gone viral overnight, earning Hobin a whopping ten million won from viewership. Drawn to the money Newtube streaming can offer him and his mother, Hobin works together with unlikely ally Jiksae to produce more videos of him fighting and see how far Newtube streaming can take them. Taking on bullies like Pakgo and other seemingly unsurpassable opponents, Hobin will either rise to the top of the streaming world or finally meet a foe he can't outsmart.

On a sunny July day in the 41st year of the Shinka Era, Jirou Hitoyoshi is tasked with covertly listening in on a secret meeting between a top government scientist and an industrial spy. However, his cover is blown, and the spy reveals himself to be an alien in disguise. Amidst the ensuing chaos, Jirou enlists the aid of cafe waitress and magical girl Kikko Hoshino, one of many "superhumans" who blend into society and secretly protect humanity from extraterrestrial threats. As a member of the government agency known as the Super Population Research Laboratory, Jirou has the dual task of protecting superhumans that defend humanity and disposing of any deemed too dangerous to live. Having proven herself a worthy ally, Kikko is invited to join the agency as its newest recruit. Fast forward five years: disapproval and distaste for superhumans are now commonplace in Tokyo. From government corruption and conflicting ideas of justice, to the morality of superhuman rights, the relationship between humans and the supernatural minority balances precariously in a world pervaded by whispers of unrest and unease. Under mysterious circumstances, Jirou has betrayed the agency, and is now a fugitive on the run. As he skulks through the rainy back alleys of Shinjuku, he is pursued by the very same superhumans that he himself once recruited.