All of the "Six-Six Fleet" armored cruisers used the same armor scheme with some minor differences, of which the most important was that the two "Asama"-class ships used less tough Harvey armor. The waterline belt ran the full length of the ship and its thickness varied from amidships to at the bow and stern. It had a height of , of which was normally underwater. The upper strake of belt armor was thick and extended from the upper edge of the waterline belt to the main deck. It extended from the forward to the rear barbette. The "Asama" class had oblique 127 mm armored bulkheads that closed off the ends of the central armored citadel.