Kamen is a normal man living at home with his parents in the United States. At 28 years old, he has black hair, brown eyes, and a full beard with red stripes. He is very strong and somewhat fast, weighing 286 pounds but not looking it. His life takes an unexpected turn when he sees a prompt on his screen that says "do you accept the price." Curiosity gets the better of him, and he clicks yes. Suddenly, a heat flows through him as a bronze gauntlet appears on his right hand, drawing him into a world he never expected.

In this new realm, Kamen encounters Caleif, a captivating demon woman with reddish-yellow hair and bluish-red eyes, whose alluring presence draws him in. As he becomes entwined in her mysterious world, he soon realizes that her arrival on Earth is far from coincidental; dark forces are at play, seeking to capture him and exploit his powers. With danger lurking at every turn and secrets waiting to be uncovered, Kamen discovers that he possesses untapped abilities that link him to this supernatural conflict. As the stakes rise, he must navigate a treacherous landscape of rival demon factions while uncovering the truth behind Caleif's past and the perilous journey that lies ahead.