Another round, The 1930 Fujimoto designs:
This warship was designed by Captain Fujimoto to replace the Fuso class Battleship, and like the one designed by Hiraga (planned to replace the Kongo class) plans to build her where canceld with the ratification of the london naval treaty in 1931.
The first design called for a treaty battleship armed with nine 16.1-inch (409mm) guns in three triple turrets, secondaries where composed by twelve 6-inch (152mm) guns in six twin turrets, unusally fitted outside the armour belt and (at least the forward turrets) protected with a shield from blast damage from the main guns; 4 twin 5-inch (127mm) AA guns mounted on sponsons at the fore and aft end of the superstructure completed the armament.
The second one increased the main guns to twelve 16.1-inch (409mm) guns and moved 4 of the 6 twin 6-inch (152mm) guns inside the armoured citadel; given the heavy armament and dimension, with lenght exceding 260 meters this design will almost certainly had broken treaty limits if built.