The movement of people from the Asian continent to Yamato Wa was almost entirely from Korea and mostly from Paekche. The idea that Japanese culture emerged in full blossom from entirely indigenous sources is at odds with strong evidence pointing to an outside influence. Prince Homuda's Paekche ancestry and his imperial descendants in the fifth, sixth, and seventh centuries explain the remarkably close cultural, political, and military ties that characterize the relationship between Japan and Paekche during this period.

Reverence towards aristocratic lineage, for example, though deeply rooted in Japan's past, is a cultural characteristic with origins in Korea and central Asia. Koguryo and Paekche kings came from the aristocratic tribes of Manchuria [Kingdom of Puyo], where the rigid social stratification defined at birth was held absolutely inviolable. The arrival of Paekche's Prince Homuda in Japan in the late 4^th century AD not only marked the beginning of a dramatic turn in Japan's cultural development, it also marked the beginning of the imperial lineage system for future Japanese rulers.

In 815 AD, Japanese scholars produced the “New Compilation of the Register of Families” (Shinsen-roku), three books containing the names of 1,182 important families (uji) living in the capital and the five surrounding provinces. Out of 1,182 families recorded in the Register, 335 were classified as imperial clans, 403 as deity clans, 328 as foreign clans, and 116 as miscellaneous clans. The scholars apparently attempted to clearly distinguish among the “imperial clans” [kobetsu] originating from the line of Paekche royal families, the “deity clans” [shinbetsu] originating from the heavenly and earthly deities, and the “ foreign clans” [shoban] originating from the important non-imperial families that came from Korea.

The first book lists 44 imperial clans that claimed descent from former emperors. “Imperial clans” refers solely to clans whose original progenitor was an emperor, rather than to the imperial family itself. Geographically, the imperial clans were located mostly in capital areas and the “deity clans” were primarily found in the provinces.

The second book lists 373 divine clans that claimed descent from heavenly deities and 30 families as descendants of native earthly deities. These clans may represent the descendants of those who came to Japan from Korea before the Yamato era, while clans that claimed descent from earthly deities may represent the descendants from the genuinely native Japanese deities.

The third book lists alien clans that claimed descent from Chinese and Korean progenitors. Among the 328 clans listed as important families of alien origin, 158 originated from Paekche, 42 from Koguryo, 9 from Silla, 10 from Imna [Kaya], and 109 from China.

Emperor Temmu (673 - 686 AD), called “the Emperor Ama no Nunahara oki no Mahito," established a new system of “Eight-Rank” hereditary titles, Yakusa no kabane, in 684 AD. The top-most ranking, called mahito (Jin - person), was granted exclusively to those imperial clans who could trace their origin back to Emperor Keitai (507 - 531 AD), Emperor Senka (535 - 539 AD), Emperor Bidatsu (572 - 585 AD) and Emperor Yomei (585 - 587 AD). Emperor Temmu's ranking system is reflected in the Register of Families, where clan ancestry was traced back through descendants from whom Emperor Keitai was selected.

The preface of the Register states that, “since mahito (Jin - person) is the sovereign one among the imperial clan names, those mahito clans in capital areas are compiled in Book One and presented at the beginning of the imperial group.”  At the very beginning of Book One of the Register, the first four mahito imperial clans listed are recorded as descendants of Prince Homuda of Paekche. The fifth clan is listed as descended from Emperor Keitai and the next six mahito clans as descendants of Bidatsu. The twelfth mahito clan is not only recorded as the descendant of Emperor Bidatsu, but also as the offspring of “the King of Paekche.”  The following eight mahito imperial clans (from the thirteenth to the twentieth) are recorded as descendants of “the Prince of Paekche.”

Emperor Bidatsu was the second child of Emperor Kimmei who was the rightful heir of Emperor Keitai. Keitai was a fifth-generation descendant of Prince Homuda of Paekche. This makes the entire mahito imperial clan, from the first to the twentieth, offspring of “the King of Paekche.”  The remaining twenty-four mahito clans, from the twenty-first to the forty-fourth, are recorded as descended from either Keitai, Bidatsu, Senka, Yomei, Jomei, Tenji or Temmu. The implication is that the entire forty-four mahito imperial clans listed in the Register can be considered descendants of the King of Paekche. It follows from this that Japan's entire line of imperial families originated from Paekche royal families.

Japan's ruling families can be said to have consisted of 335 imperial families representing the line of Paekche royal families, 373 heavenly-deity families which may represent Koreans who crossed over to Japan during or before the Yamato era, 158 Paekche families recorded among the foreign clans, and 61 families from Silla, Koguryo and Kaya. This leaves only 255 families supposedly not directly related to Koreans. Even among the so-called miscellaneous clans however, 18 clans originated from Paekche, 7 from Koguryo, 8 from Silla, and one from Kaya. Thus, out of the 1,182 ruling clans listed in the Register, only 222 clans are not directly related to Koreans (19%).