After the Battle of Midway, the IJN immediately planned a transport submarine. The type was based on the U 155 Deutschland. Her duties were the transportation of troops (110 men, 10 tons freight and 2 landing crafts) in the areas where the enemy had air superiority. Later the demands for her were changed in sequence. The final demands were 65 tons in the hull and 25 tons on the upper deck (freight only). In the beginning, the IJN did not intend to equip these boats with torpedos. Later, after strong demands from the front commanders, it was decided to equip them with torpedoes for self-defense. The I-372 class was designed as a tanker submarine based on the I-361 class. They were not allowed to be loaded with torpedoes.