Genjyo Sanzo's master and the parent who raised him, this man is the previous Sanzo priest. He picked up the baby floating down the river, named him "Kouryuu" and brought him up. He was the protector of both the "Seiten Sutra" and the "Maten Sutra", but as soon as he entrusted it all to Genjyo Sanzo, he was attacked by youkai opposition and died. That life ended at 47 years. He is endlessly good-tempered and soft-mannered, but he moves at his own pace and is a natural fool. Even so, he shows a side so philosophical it is as though he can see far into the future.

His is an old acquaintance of Goudai Sanzo, and together they spent their days as apprentice monks under the teachings of Arch-Bishop Jikaku. Koumyou succeeded to the "Seiten Sutra" and Goudai to the "Muten Sutra". Their friend, the youkai Tenkai Sanzo, walked the path of Sanzo priest with them, but with his death the "Maten Sutra" Tensan possessed was given to the care of Koumyou as well. Although this writing takes place 12 years after his death, Koumyou is a key person in "Saiyuki".

(Source: Saiyuki Wikia)