Mr. Muji is the chinese sword seller of Swords and Sandals 3.Common swords that are always found in Mr. Muji`s shop are the common quality items like wakizashi and daikatana.He also features in Swords and Sandals 4,writing the scrolls in the Caverner minigame.

He appears everytime after you level up on levels where you can spend skill points. Saying some phrases known as "Mr. Muji's advise" this is probably based off Swords and Sandals 2, in which something similar happened but without Mr Muji.