First of all, Shi Lan appeared as cold as ice. Young as he is, he is more mature than his age. At first, Shi Lan worked as a waiter in my "There is an inn". He was disguised as a man and secretive, which aroused Xiang's interest. So Xiang followed, and finally found that he was saving an injured panther. During this period, they also met the same enemy, and finally they escaped together. He and Xiang established friendship very early.
Second, Shi Lan's identity is Yuzhou Escort Agency in Shushan, whose real name is Xiaoyu. From here, it is not difficult to see that Shi Lan's real identity is concubine. Yuzhou Escort Agency is an organization of Shilan people. Maybe everyone in this organization is surnamed Yu, otherwise my brother wouldn't be named Yu Ziqi. So it's just another name for concubine Yu. In order to better hide their identity, after all, there were very few people surnamed Yu at that time, and they also had foreign descent. When Shi Lan changed into the ancient costume of Shushan, she looked even more wild. At first glance, she was not a Central Plains woman, which made the forces behind Shi Lan even more mysterious.
Thirdly, because of his identity and belief, he always maintains an indifferent attitude, but his heart is very hot, especially his feelings for Xiang, which are more and more lasting. After Xiang and He entered a mirage, only Xiang and He walked together. In the process, he helped Shi Lan's brother Yu Ziqi, and he became blind himself, which made Shi Lan feel very guilty. In this process, the two share weal and woe and support each other. This also reasonably explains why Yu Ji is Xiang Yu's only wife.