The Book of Liang (Chinese: 梁書; pinyin: Liáng Shū), was compiled under Yao Silian, completed in 635. The book heavily relied on his father, Yao Ca's original manuscript, as his comments were quoted in several chapters.
The Chinese measure of distance (li) used in the Book of Liang probably corresponds to 77 metres, as is the usage for the Book of the Three Kingdoms and other writings of the period.
Quotations on Japan and its surrounding neighbours
It contains the history of the Liang dynasty, and various descriptions of countries to the east of China. One of its best-known passages is the description by the monk Hui Shen (慧深) of the country of Fusang, 20,000 li east of China.
Wa was an ancient kingdom of Japan. Though little concrete information can be found today, its capital precinct, Yamatai, was most likely located either in Kyūshū or in the Kinki region.
"As for Wa, they say of themselves that they are posterity of Tàibó. The people are all tattooed. Their territory is about 20,000 li (1,500 kilometres) from our realm, roughly to the east of Guiji (modern Shaoxing (Zhejiang)). It is impossibly distant. To get there from Daifang, it is necessary to follow the coast and go beyond the Korean state to the south-east for about 500 kilometres, then for the first time cross a sea to a small island 75 kilometres away, then cross the sea again for 75 kilometres to Miro country (Ch: 未盧國, modern Tosu city in Saga Prefecture, Japan). 50 kilometers to the southeast is the country of Ito (Ch:伊都國). 10 kilometres to the southeast is the country of Nu (Ch:奴國). 10 kilometeres to the east is the country of Bumi (Ch:不彌國). 20 days to the south by boat is the country of Touma (Ch:投馬國). 10 days to the south by boat or one month by land is the country of Yamatai (邪馬臺國). There resides the King of the Wa people." 
"The country of Wenshen is 7,000 li (500 kilometers) north-east of the country of Wa. Over their body, they have tattoos depicting wild beasts. They have three tattooed marks on their foreheads. The marks are straight for noble people, and they are small for lowly people. The people like music, but are not very generous in spite of their affluence, and do not give anything to strangers. They have houses, but no castles. The place in which their king resides is decorated with gold and silver in a manner of rare beauty. The buildings are surrounded by a ditch, about one cho in width, which they fill with quicksilver. When there is rain, it flows on top of the quicksilver. They have many rare things in their markets. Those who are guilty of a light offence are immediately punished with leather whips. Those who commit crimes punishable by death are made to be eaten by ferocious beasts; if there has been any error, then the ferocious beasts will avoid and not eat the victim. Crimes can also be redeemed through imprisonment without food." 
"The people of Dahan are 5,000 li (400 kilometers) east of Wenshen. They do not have an army and are not aggressive. Their manners are the same as those of the country of Wenshen, but their language differs."