The handbook contains information on the tactical and technical elements of submarines that were part of the existing formations that were under construction or included in the shipbuilding programs of the Japanese Imperial Navy from October 1918 to August 1945. In addition, the quarry and combat activities of each of them are described in detail, the appearance is shown in two projections, a longitudinal section along the diametrical plane. Inside the sections, ships are placed depending on the date of laying or entry into service. The appendix contains information on the armament of boats of the Japanese fleet.