Reclusive weapons collector. He's a yakuza. He cut off his little finger as penance for being a coward when he was attacked by Oni. Yubitsume is a yakuza ritual used because it weakens a man's grip on his sword.
He owes Chris his life and his honor. He was going to run from the Oni, but running would have meant having to kill himself out of humiliation. He advises Chris to let the Oni destroy the nogitsune.