Kairu Mitsushima is a middle-aged man whose life was forever changed three decades ago when he met Daigo Umehara, a living legend in the world of competitive fighting games. Having possessed an innate talent for fighting games since his youth, this encounter cemented his passion. However, his ordinary life comes to an abrupt end following a traffic accident.

Instead of dying, Kairu is reincarnated into a fantastical alternate world. He quickly discovers that this new reality operates on rules deeply familiar to him: conflicts and battles are fought and decided using the knowledge, techniques, and mechanics of fighting games. The inhabitants of this world engage in combat where understanding frame data, special moves, and mind games is the key to survival and conquest.

The protagonist is Kairu Mitsushima, a middle-aged gamer whose decades of experience with fighting games become his greatest asset in the new world. He leverages his encyclopedic knowledge of game mechanics, honed since his teenage years, to navigate a society where such skills determine one's fate. The central conflict arises from Kairu having to adapt his real-world gaming expertise to life-or-death struggles, proving that an older gamer's strategic mind and muscle memory can overcome brute force or younger opponents in this isekai setting.

The narrative is set in a heroic fantasy world that functions like a living fighting game. The early arcs likely focus on Kairu awakening in this strange land, understanding its unique rules of engagement, and using his veteran skills to overcome initial challenges. As a newly launched manga series beginning in August 2025, specific long-term narrative arcs are still developing, but the premise establishes a journey of using profound genre expertise to conquer a world built on the very logic of competitive fighting games.