replace the four Kongo battleships with four heavy, "super" cruisers. As envisioned by the IJN in 1936, these ships, the B-65 cruisers, would mount 310 mm (12.2 in) guns, carry armor designed to withstand hits from 203mm (8 in) shells, and be capable of speeds up to 40 knots. They would be designated as "super-A-class cruisers" to signify their greater status than the A-class ships (heavy cruisers).

The plan for the cruiser class was finalized as part of the IJN's Circle Five and