Closer than real siblings

"I heard that Prince ah hai has a good relationship with the Gu family because when Princess Xinxin was stranded in the Western land, he was the one who brought her to quicksand Kingdom. Therefore, when Prince ah hai came to the great Zhou Dynasty, the elders who called her Princess Xinxin all followed her. The two of them address each other as brother and sister." The princess of Nan Lin continued.

Apart from Helian Yi and a few others, no one else in the Western Region knew Cheng huaijin's identity. Therefore, most of the versions that were spread were that Prince dugu hai of quicksand country had been called to the lange Kingdom by Yunhai under pressure. When he left the lange Kingdom and returned to quicksand country, he had saved Princess Xinxin, who had just crossed the snow Mountain at that time. From then on, the two of them became siblings.