For anyone interested in reading more on the subject try:-
Slaughter at Sea, The Story of Japan's Naval War Crimes, By Mark Felton ISBN 978 1 84415 647 4
To quote P9/10
Admiral Togo told his officers, 'The English navy is very great .. Study it. See all you can. Learn all you can ... All other navies are negligible beside it.' But even in the early twentieth century, when many British officers served in the imperial Japanese Navy as advisors and training instructors, these men noted that one important aspect of the ethos of the Royal Navy was conspicous by its absence. The Japanes, though to all intents and purposes having carefully created a carbon copy of Briatin's navy, had failed to inculcate the officers and men with the British traditions of compassion, honourable warfare, civic duty and a care of duty towards those whose ships had been sunk or were otherwise rendered helpless. The Japanese were simply not interested in these concepts as they felt them to be alien in origin and not reflective of Japanese society and military culture.
I must admit, my perception was that it was the Japanese Army that was to blame for war crimes, but it seems the IJN was just as bad e.g. it was IJN policy after a submarine attack on a merchant vessel to machine gun any survivors and liferafts.
But then maybe I looking from a 'western' perspective, if it had been another Asian country rather than Japan would the actions/morality be much different!??