Hai Seisei (裴世清)

Seisei HAI (date of birth and death unknown) was an envoy who visited Wakoku (Japan) in accordance with the orders of Yo-dai (Emperor Yang) of the Sui Dynasty in the first half of the seventh century.

Suishu (the Book of the Sui Dynasty)

According to the Suishu, Tarishihiko, the king of Wa (Japan) at this time, sent a second Japanese envoy with an official diplomatic letter to Sui Dynasty China in 607. Yo-dai was angry at the letter brought by the envoy, but he still sent Sei HAI (One of his Chinese character '世' [pronounced "Sei"] was also used in the real name [李世民] of the second emperor of the Tang Dynasty, Emperor Tang Taizong; therefore it was omitted from his name because it was taboo for people in the ancient China to use any of the characters used in the Emperor's name), a secretary, as the envoy for a return visit in 608. He came to the coast of Japan through Tsushima Island in the ocean, Ikikoku in the east, Chikushi, Shinokoku in the east (the land of Chinese), and ten-odd countries. It is said that all the countries in the east from Chikushi is part of Tai. Taio sent Shotoku (one of the twelve grades of cap rank) Ahaiichi with hundreds of attendants to meet the envoy, and ten days later, Dairai (the fifthe grade of the twelve grades of cap rank) Kata escorted him with 200 horse guards. Meeting the king, HAI told him the words of Emperor Yo-dai after receiving the words of welcome from the king. Later, HAI returned home with envoys.

Samguk Sagi (History of the Three Kingdoms)

"Samguk Sagi" (History of the Three Kingdoms) describes in the 27th volume, the 5th section of History of Baekje, as an event that occurred in March of the ninth year of King Wu of Zhou's time (Baekje), that "in March in the spring of the ninth year, bunrinro Hai SEI, an envoy from Sui Dynasty to Wakoku (Japan), passed the south of our country," which means that he came to Japan via the southern part of Baekje.

Nihonshoki (Chronicles of Japan)

"Nihonshoki" (Chronicles of Japan) refers to him as Seisei HAI, and describes as follows. The group of 12 members arrived at Chikushi with ONO no Imoko, and they were invited by Naniwa no Kishino Onari. New mansion was built on Naniwa koma-no-murotsumi. They stayed at Naniwatsu on June 15. They were welcomed by 30 ships and were lodged at the new mansion. They entered the capital on Augurst 3. The letter including 'questions to Wako from Emperor (of China)' which was brought in by Seisei HAI as "Koroji no shokyaku" (Chinese official in charge of entertaining important guests) was placed on Omikado (Emperor of Japan)'s desk by Abe no omi. He went to the great capital of Nanba on September 5, and left for home on September 11.