Second generation DDG wee the Tachikaze class
The training ship Katori, was built with a wartime role of an escort command ship, hence her frigate looks. Her aft deck could be used for helicopters, but during peace-time was used for ceremonies and PT. The large hangar-like structure was in fact devoted to class-rooms and a gymnasium.
For the Katori, I would like to thank Graham for providing source material.
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Thank you Kim for the crest
"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"