Sun Deng
When Zhang Xiu reached adulthood at around the age of 19, he, along with Zhuge Ke, Gu Tan and Chen Biao, were appointed as attendants of Sun Deng, the eldest son and heir apparent of Sun Quan. They imparted their knowledge of the "Book of Han" to Sun Deng. As Zhang Xiu was not only precise and orderly in his teaching, but also casual and friendly, Sun Deng regarded him as a close friend and often invited him to attend feasts.