In early 1942, the Ministry of Communications, with assistance from the Navy Ministry of the Navy, adopted the Standard Merchant Type 1A cargo design. The Type 1As were not significantly different from peacetime designs, with machinery amidships. Construction took about 90 days.
The Type 1As included NICHIYO, DAIBU, DJOKJA, GETSUYO, KENWA, KOYO, MITSUKI, TATSUNAN, TATSUURA, UYO, YAMAMIYA, YOWA and YOZAN MARUs.
| Builder: | Kawaminami Kogyo K.K., Koyagishima |
| Years Completed: | 1943-1944. |
| Gross Tonnage: | 6400-tons (nominal). |
| Dimensions: | 445'10" x 58'5" x 32'2" |
| Propulsion: | 3 steam boilers, turbine, 3500 s.h.p, 1-shaft, maximum speed 15 knots |
| Armament: | Various AA gun protection |
