It is assumed that the Imperial Japanese Navy (IJN for short, Japanese Nippon Kaigun) was formed in 1869, ie in the Meiji era, and from around 1920 it was the third maritime power in the world. It was formally dissolved in 1947. This navy, illuminated by considerable successes in the war with Russia in 1904-1905, developed intensively in the interwar period (1919-1939), especially in the 1930s, introducing many great classes of ships into service - to mention, for example, the phenomenal for its time, destroyers of the Fubuki type or the project of battleships of the Yamato type - but also very successful naval weapons. This is especially true of the famous "long lance", the 610 mm Type 93 torpedo, which outclassed similar Western designs with its performance. Sea aviation was also successfully developed. It can be assumed that in the years 1937-1941 alone, ships with a total displacement of nearly 350,000 standard tons entered service in the IJN! What's more, the people serving on these often very valuable ships were subject to a regime of even iron discipline, but also (especially in the case of officers) had careful and excellent training. For example, it is assumed that Japanese naval officers were outstanding navigators, good tactics, and generally very demanding opponents, as evidenced by the first months of the Pacific War. In Japan, until today, the most outstanding of these officers is Admiral Isoroku Yamamoto, who was responsible for developing the plans for the attack on Pearl Harbor (1941) and the first months of the war in the Pacific Ocean. However, from 1942 and the Midway defeat, the IJN began to succumb more and more to the quantitative and technological advantages of the US Navy. She also did not attach enough importance to the development of on-board electronics (especially radars) or the activities of the ZOP, which over time had a disastrous effect on her.