This article contains details from the manga that are not covered in the anime. Proceed with caution.
He had dark eyes and long, straight black hair which he tied loosely behind his back. He wore long robes similar to King Hiryuu's.
Due to his brief appearance in one of Zeno's flashbacks, his personality didn't receive much elaboration. However, he seems to have been a serious young man who trusted Zeno's advice and cared for the safety of the kingdom.
He‘s the second king of the Kouka Kingdom.