In this world, there exist demon swords. Those who have the sword will have their will taken over, and they will lust for human blood and keep on killing indiscriminately. The sealer is who searches for those blades that haunt people and seal them with his scabbard.
Season 1
Osagami Kakeru is a master who is tasked with the mission of sealing the blades of filth called Kegareyaiba born from the dark sides of people's hearts.