Rio

In this adventure, Kunioka saves the life of Manaka Takuya, a part-time freelance assassin who botches a big gun procurement assignment. Due to this incident, Manaka is suspended from the hitman association and his father, the former number one ranked hitman in Kyoto, drags him back to the family home to do chores. When Kunioka checks up on his former brother-in-arms, he finds Manaka has become domesticated but the reappearance of unioka reawakens Manaka’s fighting spirit and the young man challenges his father to a duel as part of his return to walking the path of an assassin. In order to defeat his father, however, Manaka will have to embark on intense training…

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.