I saw this program on TV just recently, which sparked an enthusiastic glow..
The program itself was a somewhat waste of time (about the building of the Panama canal...), but at one point they included some brief information about this Japanese submarine, which supposedly was built to attack the canal and similar stuffs..
The little information the program (of course, not the name...) shared, was that it was built in a too late phase of the war, so it was never really put to use (I _think_ they only built a couple.. all except one or so which was now in a US museum or something..), was a relatively huge submarine, and the cool thing, it could launch an airplane when surfaced, which was stored benath deck when submerged...

any one have _any_ idea where one might find more information about this vessel? please, I feel an urge to model it.. !