It's a family business, led by three generations of the Okamoto family:
- grandfather Kitharo Okamoto founded a repair shop for audio equiment in Tokyo in 1919, called 'Kiwaya Shokai'. I suppose Kiwaya is an abbreviation (first letters of his first name, the rest implying grammophones or electronics), Shokai simply means Retail Business.
- grandson Ryoji Okamoto became CEO (of a modest firm of about a dozen employees at its height) in 1957 and branched out in ukulele production. His brand was 'Famous', it was mostly produced in own workshops. He was late to that market which already had stiff competition (Luna made at Mituba, Toshiba, Kiso Suzuki and Nagoya Suzuki, Aria, Star made by Hoshino/Ibanez) but thanks to his focus on quaility (actually copying Martin's specification), endorsements by artists and sheer stubborness he was the only one to survive as a ukulele manufacturor. In fact, at the end of the 1960s he even sourced the lower end part of his ukulele line from his former competitors, the Mituba factory - or Mituba Gakki if you like to learn Japanese. Why he chose 'Famous' as a brand name is probably to emphasize the exotic American quality of the instrument. So the labels read 'Famous, by Kiwaya'.
- The company started dominating the Japanese market during the 2000 resurgence of the ukulele, and were only occassionaly sold in the West. But when Ryoji's daughter Kyoko Hara took over in 2002 she launched an export brand, simply called 'Kiwaya' (patented as a ukulele brand in 2008), a US dealership through Takuli and innovation in the ukulele line (bamboo, custom builds, eco series, k-wave rock series, ...).
It's perhaps confusing, but Kiwaya is at the same time a shop (which sells Kamaka, Koaloha, genuine Martin and even most other Japanese brands), a dealership (which imports LoPrinzi to Japan), a manufacturer (which makes Famous and Kiwaya ukuleles) and a brand in itself.
The difference between Famous and Kiwaya ukuleles is that the former is intended for the Japanese market, the latter for export. But because of that both brands weren't and aren't exact copies of each other: Kiwaya tend to be more 'upmarket' in apoointments and price.