Who is Kenzo from The Samurai's Garden and what is their importance?

Kenzo is Matsu's best friend as a young man and the man betrothed to Sachi when she discovered she had leprosy. Kenzo never married, though he would have been free to do so after Sachi's apparent suicide. Kenzo owns and operates a tea house in Tarumi and is called the "best rice cake maker" in the area. Kenzo's thoughts regarding Sachi are never revealed, but he is quite angry when he discovers Sachi at Matsu's house. It's only shortly after that time that Kenzo commits suicide, hanging himself in his tea house.