The Japanese were buying British ships, but their first domestically designed battleship was Satsuma, authorised in 1904 and carrying 4x 12in and 12x 10in guns. She was roughly analogous to the Lord Nelson class, but closer to Dreadnought in terms of armament, displacement and performance. If they had gone with big guns, she would have been a dreadnought, although she was still finished too late (1910) to be the first. The Kawachi class dreadnoughts, commissioned two years later, were also built in Japan. The carried 12x 12in, but these were a mix of 4x 12in/50cal and 8x 12in/45cal. This was done to save money apparently, but caused a fire control headache as the two types of gun obviously had different ballistic properties.
It's hard to imagine a dreadnought aiming her guns the same way Victory did at Trafalgar, but it very nearly happened, and the RN lagged behind the Germans in fire control right up to 1945 - British gunnery in the final stages of the Bismarck engagement was so poor that Tovey famously remarked that he might as well throw his binoculars at the German ship. The Dreyer system initially used by the RN was nowhere near as good as the civilian-designed Pollen system that it plagiarized and then beat into production, nor were British optics as good as German ones. The positioning of the director station near a funnel in early British BBs and BCs also made them almost unworkable in combat, with temperatures in the perch becoming almost unbearable. Better than closing to 2000 yards and firing 10 guns individually though...