The older brother of Okoi; he is able to assume the physical appearance of others and imitate their voice. He was slain by Ofuku's samurai through Tenzen plot in episode 21, and Tenzen himself was at the scene. He was the eighth of the ten Kouga ninja to die; and also number sixteen of 20 ninja to die.
Saemon was chosen by Kouga Danjo to be one of ten shinobi to represent their clan of Kouga Manjidani against the chosen ten of the rival Iga Tsubagakure clan. Saemon is perhaps Basilisk's most complex character. Cool and aloof, he conducts himself in both war and peace with an almost professional sense of detachment. The only person he shows emotion to is his younger sister Okoi with whom he shares a deep bond. Following Okoi's brutal capture, interrogation, and terrifying death at the Iga's hands; Saemon throws himself whole-heartedly into the war between Koga and Iga, viewing victory for his clan and revenge for his sister as one and the same. To that end, Saemon will use any method necessary to physically and mentally break the remaining Iga ten. But after the fight is over and his enemy is dead, Saemon will always apologize to his slain opponents with the hope that in death they might know the peace they were denied in life.
Along with Kasumi Gyoubu, Saemon specializes in stealth and infiltration. By pressing another's face into a raised mound of mud or soft clay, Saemon can form a mold with which he can insert his own face into, taking their form and appearance for himself. This, along with his talent for impersonating voices, makes Saemon a master of disguise. His technique however is only effective cosmetically. It doesn't bestow him with any of a person's memories or abilities and anything with senses superior to a human's (as Hotarubi's snake proved) are able to see through it. Saemon is also one of the Kouga's more capable fighters, at one point successfully defending himself against multiple Iga ninjas at once.