>>49015951
The museum of the Yasukuni shrine has some naval stuff, for example a kaiten, a D4Y dive bomber and one of Mutsu's casemate guns, but i don't know if it's worth the entry money for that alone. However, they have a Zero in the entrance hall that you can visit without actually entering the museum, so that might be an idea. Another Zero is at the Museum of Nature and Science in Tokyo.
Close to the Mikasa there are memorials for Yamashiro and Nagato, among others. A Naka monument is located in Oarai, but that's almost an hour with the train and most likely not worth the time and money (if you aren't also a Girls & Panzer fan and want to see the town anyway).