It's tempting to give the standard response -- 90% of all logos are custom lettering/fonts -- but in this case, Japanese type design is so little known in the West, that I wouldn't stake much on that statement (even though it still seems likely to me).

When P22 had the Font Pavilion collections of Japanese typefaces, I was amazed at the variety of unfamiliar Latin alphabets that were included among all the Japanese character fonts. Now, as you see, most of the collections are sold out, but you can still look at samples of the fonts.