Zhoushan Xuan (Hànzì: 玄周善, Pinyin: Xuán Zhōushàn, On'yomi: Gen Shūzen), more commonly known as Master Zhoushan, is the master at the Guang Martial Arts School who has a deep knowledge in the martial arts and the wude.
Ryo Hazuki first meets Master Zhoushan when learning about the wude. He tells Ryo he is not qualified to tell him about the wude because he ruined his disciple Zongquan Bai's life. He feels it is all his fault that Zongquan has fallen into the role of a street performer. Once Ryo meets Zongquan, he gives him a letter to give to his master. He delivers the letter to him and Zhoushan tells him one of the wude "JIE".
On the day after Ryo saves Guixiang Lee from the landsharks, if he walks by the Guang Martial Arts School, he will be stopped by one of the assistant instructors Mingzhen Ye and he will tell him that Master Zhoushan wants to see him. He will then teach him a grappling move called "Wild Throw".
- Master Zhoushan's zodiac sign is Virgo and he has a O blood type.