Question: Who is the sibling of Shu Yu from the Chinese capital that Kanmu modeled his government after?

Knowledge 1: Heian period
When Emperor Kammu moved the capital to Heian-kyō (Kyōto), which remained the imperial capital for the next 1,000 years, he did so not only to strengthen imperial authority but also to improve his seat of government geopolitically. Nara was abandoned after only 70 years in part due to the ascendancy of Dōkyō and the encroaching secular power of the Buddhist institutions there. Kyōto had good river access to the sea and could be reached by land routes from the eastern provinces. The early Heian period (784–967) continued Nara culture; the Heian capital was patterned on the Chinese Tang capital at Chang'an, as was Nara, but on a larger scale than Nara. Kammu endeavoured to improve the Tang-style administrative system which was in use. Known as the ritsuryō, this system attempted to recreate the Tang imperium in Japan, despite the "tremendous differences in the levels of development between the two countries". Despite the decline of the Taika-Taihō reforms, imperial government was vigorous during the early Heian period. Indeed, Kammu's avoidance of drastic reform decreased the intensity of political struggles, and he became recognized as one of Japan's most forceful emperors. [SEP] Knowledge 2: Shu Yu of Tang
According to the Records of the Grand Historian, one day, King Cheng of Zhou was playing with his younger brother, Prince Yu. King Cheng of Zhou suddenly picked up a parasol tree leaf and gave it to Prince Yu. Then he said playfully," Let this be a proof that I will make you a feudal lord." Prince Yu happily got the leaf and he then told this to the Duke of Zhou. The Duke of Zhou thought that whatever the young King Cheng of Zhou said should not be taken lightly since he was the king.
Knowledge 1: Heian period
When Emperor Kammu moved the capital to Heian-kyō (Kyōto), which remained the imperial capital for the next 1,000 years, he did so not only to strengthen imperial authority but also to improve his seat of government geopolitically. Nara was abandoned after only 70 years in part due to the ascendancy of Dōkyō and the encroaching secular power of the Buddhist institutions there. Kyōto had good river access to the sea and could be reached by land routes from the eastern provinces. The early Heian period (784–967) continued Nara culture; the Heian capital was patterned on the Chinese Tang capital at Chang'an, as was Nara, but on a larger scale than Nara. Kammu endeavoured to improve the Tang-style administrative system which was in use. Known as the ritsuryō, this system attempted to recreate the Tang imperium in Japan, despite the "tremendous differences in the levels of development between the two countries". Despite the decline of the Taika-Taihō reforms, imperial government was vigorous during the early Heian period. Indeed, Kammu's avoidance of drastic reform decreased the intensity of political struggles, and he became recognized as one of Japan's most forceful emperors. [SEP] Knowledge 2: Han dynasty
China's first imperial dynasty was the Qin dynasty (221–206 BC). The Qin unified the Chinese Warring States by conquest, but their empire became unstable after the death of the first emperor Qin Shi Huangdi. Within four years, the dynasty's authority had collapsed in the face of rebellion. Two former rebel leaders, Xiang Yu (d. 202 BC) of Chu and Liu Bang (d. 195 BC) of Han, engaged in a war to decide who would become hegemon of China, which had fissured into 18 kingdoms, each claiming allegiance to either Xiang Yu or Liu Bang. Although Xiang Yu proved to be a capable commander, Liu Bang defeated him at Battle of Gaixia (202 BC), in modern-day Anhui. Liu Bang assumed the title "emperor" (huangdi) at the urging of his followers and is known posthumously as Emperor Gaozu (r. 202–195 BC). Chang'an was chosen as the new capital of the reunified empire under Han.
Knowledge 1: Heian period
When Emperor Kammu moved the capital to Heian-kyō (Kyōto), which remained the imperial capital for the next 1,000 years, he did so not only to strengthen imperial authority but also to improve his seat of government geopolitically. Nara was abandoned after only 70 years in part due to the ascendancy of Dōkyō and the encroaching secular power of the Buddhist institutions there. Kyōto had good river access to the sea and could be reached by land routes from the eastern provinces. The early Heian period (784–967) continued Nara culture; the Heian capital was patterned on the Chinese Tang capital at Chang'an, as was Nara, but on a larger scale than Nara. Kammu endeavoured to improve the Tang-style administrative system which was in use. Known as the ritsuryō, this system attempted to recreate the Tang imperium in Japan, despite the "tremendous differences in the levels of development between the two countries". Despite the decline of the Taika-Taihō reforms, imperial government was vigorous during the early Heian period. Indeed, Kammu's avoidance of drastic reform decreased the intensity of political struggles, and he became recognized as one of Japan's most forceful emperors. [SEP] Knowledge 2: Heian period
The Heian period was preceded by the Nara period and began in 794 A.D after the movement of the capital of Japan to Heian-kyō (present day Kyōto京都), by the 50th emperor, Emperor Kanmu. Kanmu first tried to move the capital to Nagaoka-kyō, but a series of disasters befell the city, prompting the emperor to relocate the capital a second time, to Heian. The Heian Period is considered a high point in Japanese culture that later generations have always admired. The period is also noted for the rise of the samurai class, which would eventually take power and start the feudal period of Japan.

Answer: King Cheng of Zhou