Chef Muramasa is a non-player character in Devil Summoner: Soul Hackers. He serves as an assistant to the player in terms of fusing demons into swords.
Muramasa works as a chef in the galley of the Hotel Goumaden cruise liner. In addition to his day job, he has been practicing the art of fusing demons into blades. After the events of the Auto plant dungeon, the protagonist and Nemissa are directed to Madame Ginko, who provides the Nameless Sword and refers them to Masamune. He can fuse one demon into the swords, changing its properties based on the type and strength of the demon in question.
In the 3DS remake, he also has a Sword Compendium which allows sword fusions to be recorded and repurchased again (in order to purchase from the sword compendium, you must sell or discard your current fusion sword).