I visited the Museum of Japanese Emigration to Hawaii in Suo Oshima Island in Yamaguchi prefecture with my client who came from Hawaii. He is the third generation(Nikkei San-sei) and was looking for his ancestor's root. This museum displays the history of emigrants, pictures and video. It has also a big data base for searching the record of emigrants who moved to Hawaii from 1885 to 1926.
After 4 hours researching, I and my client finally found the record which includes "the prefecture of birth, birth date, departure date, traveling purpose and occupation" of his ancestor. According to the stuff of the museum, they have about 135000 people's record and recently about 10 % visitors come from Hawaii to find their family roots.
My clients said that this visiting was very meaningful. If you'd like to know about it more or need help to visit there, I'd be happy to support and share about the information. Please feel free to contact me.