The present watch is one of the exceedingly rare wristwatches made by Seikosha for the pilots of the Japanese Imperial Navy in the 1940s.
The Seikosha company was established in Tokyo, Japan, in 1892 as the clock manufacturing branch of K. Hattori, a jewellery and watch firm that opened in the early 1880s. Over the years, Seikosha was divided and subdivided into a collection of smaller companies which later evolved into what is known today as the Seiko Corporation. Seikosha was especially well recognized for their production of military watches, including ship chronometers, wall clocks, pocket and wristwatches.
For an illustration and description of a similar watch see Militari da Polso by Leopoldo Canetoli and Francesco Ferretti, p. 100.