honestly i think this should also be added to gameplay mechanics but i'm not entirely sure it fits(torpedo cruisers need midget subs to do preemptive attacks, so its kinda a required equipment for them).
Oh and for those who don't know, kaiten is a man-operated midget submarine which is similar to a kamikaze plane, in short, human torpedoes. In game, Kitakami had certain issues with these weapons which portrayed her real-life counterpart that did not fire any of these weapons despite being the initial test ship for it and the largest ship to be armed with kaitens.