As we lack anymore info then the proposal/design date (Around 1941), type (Heavy Cruiser) and armament (203mm Guns)
It's anyones guess what the IJN wanted or what was the base specifications.
Still we have multiple options:
Twin turret variants:
1. Simply an Improved Mogami with fixed turret placement (enough space between the 1st and 2nd turrets) and guns eg 203mm/50, 4x2 10cm DP-AA guns and improved armour say 120 and 150mm belt and 40 and 60mm Deck. Hull wise similar to Ibuki but a bit longer: say 200-202m WL and 21-21,5m wide. Engien would either remain 152K shp or improved to 160K shp to retain the speed.
Ibuki or Tone style simplified Bridge and or mixed with elements from Oyodo and Agano
This would likely require the least costs and least development time.
2. Enlarged Mogami with 5-6x2 203mm/50 Turrets and Uniform armour of 145-150mm Belt and 50-60mm Deck, possible but not necessary a small seaplane hanger (Smaller than Oyodo's). 4-6x2 10cm DP-AA and improved/modified bridge, taking into account the experiences with Mogami and Tone classes and maybe re-design the Takao bridge with the Tomozoru incident in mind. Longer and Wider hull with a 21,5-22m width and depending on turret number 205-225m Long to retain the high speed.
Triple Turret variants
3. Using the Enlarged Mogami hull as a basis but changing the armament to 3x3 203mm/50 guns and the usual 4-6 10cm DP-AA guns, alternatively a sort of mini B-65 battlecruiser look with appropriately reduced hull and superstructure elements.
4. Using the Tone as a basis for a Scouting oriented or Aviation Cruiser, all 3 triple 203mm/50 turrets forward and seaplane facilities aft like on Tone or my Tone-kai drawing. Hull is similar to that of the Enlarged Mogami
5. Modified version of the above but adding a 4th triple turret aft, seaplane hanger is optional, not installing it would likely allow a shorter hull
6. Using that fake design drawing as a basis but using actual 203mm/50 guns in 4 triple turrets and actual IJN design choices and elements. Or alternatively a sort of reduced B-65 design with 203mm turrets and smaller hull.
Al designs had 4 quad 61cm Torpedo Tubes.
