for those snickering few--did the question really go that far over your head? in other words, how would the Japanese prepare the defense of a probable/likely invasion beach on Honshu, within the time frame of 1943-6/44, based on all their experience up to that time.
they had better terrain for starters... there are several good works on this
"Hell to Pay: Operation Downfall and the Invasion of Japan" (really good for specifics of deployment and plans)
"Downfall: The end of the Japanese Empire" (a larger overall look)
"The Invasion of Japan: Alternateive to the Bomb" (again more of a general look)
I haven't read this one yet but it looks interesting
"Defense of Japan 1945"
my take is that there isn't a lot to choose from in terms of plans. The Japanese had their 2nd and 3rd rate units (In terms of equipment and training) manning fortress positions on the coast with their better trained and equipped 1st rate units held back in reserve. Which mirrors pretty closely the German deployment in Normandy, more so if the 12th SS and Panzer Lehr are moved up a little closer to the invasion area (as Rommel was pushing for). The Japanese, because of the relative smaller size of their potential invasion area had more depth and took advantage of that.
The Japanese had far less resources than the Germans at this point too, but if they had them, such as the large numbers of mines, they would definitely have used them similarly. The Japanese were weak in dealing with airborne attacks, but they really only saw 2 brigade sized airborne drops in the Pacific and a few in Burma unlike the major assaults in the European theater. German armored doctrine is obviously superior of course.
Both the Germans and Japanese depended on moving up their reserves and assumed they would suffer air attack. We know how well that worked in Normandy but we don't know how it would have worked in Japan. Again the terrain is the issue there