Shuqin Zhang (張書勤 Zhāng Shūqín) is the aide of Yuanda Zhu.
Ryo Hazuki first meets him after setting up the Chawan Sign at the Dou Jiang Diner. Zhang, unseen, gives Ryo a note instructing him to meet at the diner at 8pm. At 8pm Zhang enters the diner; shortly after appearing, members of the Yellow Heads break in and capture him. Ryo fights off the men and rescues Zhang. Zhang reveals that he has no idea about Zhu's current whereabouts as he has hidden himself from the Chi You Men. However, Zhang tells Ryo to seek a dangerous man known as "Ren of Heavens" as he might know where Zhu is.
Later on, Zhang follows Ryo to Kowloon in order to help in their investigations on Yuanda Zhu. However, because of his connection with Zhu, he gets captured again by an executive of the Yellow Heads Yuan, leading Ryo and Ren to rescue him.
At Ren's Hideout after being rescued from Yuan's Room, he reveals that Zhu is located on the 10th floor of the Ghost Hall Building. He then gives him a key with a Snake and Tortoise on it telling him to look after Zhu.
- Zhang's zodiac sign is Scorpio and he has a A blood type.