so i quess the japanese are still going to have the german viic.
There are a couple of Jap subs that have hull shapes similar to U-Boats but the conning tower is different, the Type J2 in paticular comes to mind.
There is a old saying: "Form follows function".
Here is a list of all the Jap sub types that served in WW2. http://www.combinedfleet.com/ss.htm