This seems to be the only product of the Prince Camera Co., dated by Sugiyama to 1955 (the McKeown's entry seems to just replicate Sugiyama). Sugiyama does however, show a 1939 "Prince Baby Ref" fixed focus pseudo-TLR attributed to Prince Camera
Works. There may be an association here, although neither company name variant shows up anywhere on the Web; it seems surprising that a camera company could stay in business over 16 years between producing only two models.
The Prince name was used by Fujimoto Manufacturing Co. for several prewar models, including a "Prince Flex" TLR in 1937, which is a
rarity apparently modelled roughly on the Ikoflex "Coffee Can" of a couple of years earlier (see my Ikoflex page in the German section).
This Prince Junior is in nice condition and seems well-built for a small-volume product. Serial number 9016.
Taking lens is J-Luminar 80mm f3.5
Shutter Ceres 1 to 1/300