Hosco is a Japanese Company with a predominantly Japanese website so I run into difficulties working it all out. The history is, (I believe), they started in 1983 as "Saga Japan", a Japanese buying agency for Saga Musical Instruments (USA). In 1995 they became incorporated and changed the company name to "Hosokawa Co., Ltd.". In 2007 there was another name change, this time to Hosco, (trade mark registered in 2011), and in 2008 they started their own development and sales of musical instruments and tools under the HOSCO brand to go with all of the stuff they already distributed. How much of a link there still is to Saga Musical Instruments I'm not sure but they certainly distribute some brands in Japan that Saga distribute in the US. Though they have started an international English version of their website it is still much smaller than the Japanese website and it is difficult to work out what brands they own and what they just distribute, (but I'm guessing part of the reason for the larger Japanese website is this includes the stuff they are the Japanese distributor for?) 

This is what I can make out from the website. They own a factory in China that produces Guitars, (Andalusia, Reuben, Scooh'z) and probably other instruments. They own a factory in Japan that produces luthiery tools and parts, and are worldwide distributors for Gotoh machine heads, (but I'm not sure if they own them?). 

On the Ukulele front - They produce a number of Hosco branded Ukulele making kits. They own the Regal name and distribute the current ukuleles, made in China and branded Regal made in China (This isn't mentioned on the website but they confirmed this to me in an email). They produce a range called Lahaina Ukuleles consisting of Sopranos and Concerts with the better ones having a special offset nut to improve intonation. Production of these appears to have started in about 2011, (and they are nothing to do with the earlier use of the name by Kala but as Kala still own the brand name; these may only have been available in Japan and production may have ceased by 2013?) They are still using the name though for Chinese produced plastic body Banjoleles, (the same as GoldTone brand as Little Gem), in Japan

They own Minmin Eco, that use to include a Ukulele made from laminates produced using wood harvested during the thinning process needed to ensure healthy growth in Japanese managed cedar forestry, but now it's only strumsticks.

They have taken over the Vietnamese operations of Winkler Woods and now own and distribute the ukulele brand Big Island. Whether or not Winkler still supply the koa for these I don't know? The Ukuleles are made in Vietnam and they are fairly traditional in their design, (but don't have a Spanish heel), all solid wood, (koa or mango), and come as Soprano, Concert and Tenor models. They have a good reputation for Vietnamese made Ukuleles, possibly due to Winklers wood supplies? In 2006 Big Island introduced a second range, Honu with a turtle on the distinctive headstock, (Honu is Hawaiian for turtle), instead of a picture of the Big Island. These too are made in Vietnam and are also quite traditional in their looks. With the take over the separate names have stopped and they are all Big Island but some still have the turtle headstock.