Yuuki and his classmates are cleaning the classroom, and everyone compliments him on his cleaning skills, even though it’s nothing to brag about.
Later that day, Yuuki is trying to figure out what to do with his future and searches for a job. However, the world is not that simple, and turns out quite dangerous at times.
Suddenly, as he walks, he is teleported to an alternate dimension, or Mato, where shuuki monsters roam attacking humans.
There is quite a protocol established, and he is instructed to hide until the Demon Defense Force arrives to rescue him.
Unfortunately for him, he is immediately spotted by a shukki, forcing him to run away.
He is cornered, but Kyouka, the chief of the Seventh Unit of the Anti-demon Corp, intervenes just in time and slices the shuuki down with her sword.
Outnumbered, they make a run for it, and end up being chased by the shukki. On their way, they are helped by Himari, Shishu, and Nei.
They shoot down shukki from their vehicle and tell their commander that they saved a little boy. The boy regains consciousness, and asks for his sister.
Kyouka and Yuuki spot the boy’s sister escaping from a shuuki. Somehow, Kyouka rescues the girl and protects them. But they are running out of time, and Kyouka offers Yuuki the chance to help.
In order to defeat the shuuki, Kyouka can use her unique power to turn other shuuki into slaves, but now promises Yuuki to grant him incredible powers as her slave.
He hesitates for a minute, but he ends up accepting, after all, he wants to makes a difference in this world.
She sticks out her finger and he instinctively licks it, transforming him into a giant beast.
He possess incredible strength, and takes down the shukki easily. They manage to escape, but the remaining shuuki fuse into a huge creature and attack again.
The creature is no match for Yuuki’s brute strength, and they are saved. Now, to comply with the power bestowed on her, Kyouka has to reward Yuuki for his job.
Yuuki does not understand her behavior, she tries to explain him it’s not something she can control, and she kisses him passionately.
Kyouka explains Yuuki how the real world is in danger, and that she intends to become the Supreme Commander and lead the Demon Defense Force in the future, and thinks he could help her.
Yuuki starts to think he has found the perfect job for him, Kyouka takes him to the Demon Defense Force’s Dorm just to introduce him as the new caretaker and housekeeper.
(魔都精兵のスレイブ)
