By my research, Nitto was an entirely Japanese brand. While it may appear to be a Columbia client machine, it had no affiliation with either Nitchiku aka Nipponophone aka Nippon Columbia. Nithiku had ties to both Columbia Graphophones (US and UK) with the latter having the most direct impact when Ltd (UK) acquired a dominant share of Nipponophone in 1929. From then on, Columbia Japan adopted all of British Columbia's design features, such as the lid record storage inverse "V," the No.9 sound box, the 15a (renamed the 15 for the Asian market), the Number 8 (reverse gendered and renamed as the No 16) and other Viva-tonal Grafonola trademark and patented designs. From its (then) US sibling, it brought in a few of the larger machines including the Kolster-Columbia phonograph-radios, but as it did with the British designs, Nippon Columbia soon began to develop its own unique models.
By the mid 30s, soon before EMI severed ties, Nippon Columbia had attained such prominence in Japan and the markets beyond S.E. Asian and Australia (to the point their machines were exported to Europe and competed directly against EMI) that the inevitable "clones" began to appear.
The Asian market had then, as it still has in a few places now, a looser/more cavalier approach to "intellectual property." This is why many Japanese gramophones of various names and quality found today bear eerily similar (i.e., directly copied) components a la both Nippon Columbia and JVC (The Victor Co. of Japan) but with different branding and other miscellaneous details entirely. While Nippon Columbia had it's economy line of "Eagle" machines* (a name leftover from Nitchiku's early affiliation with Columbia US akin to Columbia Graphohone Ltd's "Academy" in the UK in the 30s, "Regal" prior to that, and "Harmony" in the USA), Nitto was not one of these bottom shelf lines and did not use Nippon Columbia manufactured parts. Nitto unashamedly took great "inspiration" from Nippon Columbia's (and by extension, the western Columba's) IP and directly competed against the machines they "emulated." As seen by many via the machines brought home to the west post WW2 and during the years of "Occupied Japan" and Korea, the clone machines market was a prolific one, with a few of these companies contracting as OEM for a few minor American (mostly West Coast) "off brands." From what I've observed, the clone manufacturers survived well into the 50s and some into the 60s, especially as aftermarket parts suppliers for the markets in Africa, S. Asia, etc.
Back to years of lurking...
Arvin
*a few of which made it to Europe pre and during WW2 in such countries as Switzerland