I found a scholar of ancient Korea and Japan history.
Professor Wontak Kim of Seoul National University wrote a book about the relation between Baekje and Wai in the year of 2003. He taught Economics in the university but he is a famous amateur histiran especially in ancient Korean history. He was shoked when he read a paper read Korea was governed by Japan in the ancient age, and researched to make the western world not to misunderstand the historical fact. He concludes in his book, Baekje invaded Japan and found a country named Yamato Wai.
Here is his web page.