Koda is a huge, dark skinned man. He wears rough clothing and has a jagged scar encircling his entire neck He smells terrible and oozes arrogant confidence.
He was first encountered when he threw Usagi Ozaki through the wall of a building and then hurled a vendor's cart at him. He fought savagely, with a single-minded focus on his target and no concern for his own life. When defeated, his body melted into a black goo that burned the skin when touched.
According to Ozaki's letter to Usagi Tomoe he had decapitated him previously some months earlier in Ryoko Owari. Presumably explaining why he was shocked to see him again.
He was encountered a second time on Kitsune Hamato's boat. This time bearing scars consistent with the wounds that felled him in Yasuki Yashiki. Once again his body melted into goo upon his death.