In the Land of the Rising Sun, the conflict between Muzan Kibutsuji and his demon entourage and the Demon Slayer Corps has been going on for a thousand years. Common slayers decapitate demons. Six Lower Moons eat common slayers. One of the six is eventually decapitated by a Pillar. Pillar is then devoured by the Upper Moon. And so on and on. Will one heavy smoker finally break this age-old impasse for either side?