Last bits and pieces I will post here for the Japanese Navy. The Japanese built all sorts of escorts, sub chasers, minesweepers, minelayers, and submarines.
Like a lot of navies, the Japanese did not need purpose built minelayers, such as the French and British had built. Their cruisers and destroyers could be fitted for minelaying.
The Japanese also had minelaying submarines and aircraft carrying submarines. The I-400 class aircraft carrying submarines were part of the plan to put the Panama Canal out of action. Stop the Americans transferring ships, to and fro, from the Pacific to the Atlantic and back again. New ships commissioned in the Atlantic would have to go round the bottom of South America or Africa to make their way toward the Pacific. That event is actually something the Japanese should have had as part of their opening moves. Take out the US Pacific Fleet and destroy the Panama Canal.
The Japanese had seen the use the Germans had made of armed merchant cruisers (raiders) and had tried building their own but did not have the same attention to disguise as the Germans. By the time this ship went to sea the days of the raiders were already over. The two 'raider' ships of the Japanese operated in the South Pacific and Indian Oceans during 1942, and with the loss of the second ship, the Aikoku Maru was transferred to ancillary duties. The ship was used to run troops and supplies to Guadalcanal.
The Japanese recognised the need for reconnaissance and also the need for ships to be able to supply and maintain the reconnaissance aircraft. Although a lot of the purpose built seaplane carriers were repurposed to aircraft carriers, two or three were kept for their original duties.
All of these are real life Japanese ships and need no alterations by me to do their duties. That is it from me for the Japanese Navy. I am thinking up some battle plans for the Japanese that include my alternate opening attacks by the Japanese to include the destruction of the Panama Canal. Giving the Japanese some extra aircraft carriers makes this a possibility. What would happen if the Japanese put a depot ship and a squadron of submarines at the Galapagos Islands and Juan Fernandez Island, to interdict the shipping that would have to be routed around the bottom of South America. All sorts of possibilities open up.
W.6. minesweeper