Kongo was actually built by Vickers (and was
the last Japanese capital ship to be built outside of Japan), while the
remaining three were built in Japanese yards. During the inter-war
years, all of them were upgraded in terms of propulsion and protection,
and were re-rated as battleships.
KONGO is the only IJN battleship sunk by a submarine during the war and the last battleship ever sunk by a submarine.