Narukami Ryusei is your typical NEET, spending his days locked in his room playing video games and living a carefree, lazy life. However, Ryusei was once a powerful demon king in another world! So why not enjoy this new life to the fullest? But he’s not the only one reincarnated; the hero who defeated him is here too—and she’s an adorable high school girl?! Can Ryusei navigate this new world while facing his old enemy, or will he find himself in battle once again?