Dave Homewood wrote:
The Royal Navy had radio-control guided un-manned aircraft in 1935, the de Havilland Queen Bee. So the technology was around long before 1944.
Sure, the Brits and Americans had done a lot of research and use in the technology and countermeasures to that technology against some of the German weapons, notably the Hs293. I don't believe though the Japanese were that far along. If they were, were they privvy to the succesful jamming of the 293 guidance? I dunno much about the Japanese "skunk works" stuff, but recall they did have some promising potential with a radar-guided surface-to-air weapon as well as a very promising heat-seeker designed to target the hot spots on bombers. Too little..too late.
Revert to the simplest, cheapest, and most devoutly determined guidance system ever to aspire to heavenly destination...Mark-1 mod-0 recruit with almost 1000 years of militaristic DNA in his cultural genes.

EDIT
I skipped mentioning the Japanese did have a radio-guded bomb they were working with which was similar to the Hs293...dunno how successful it would have been given the Allied available countermeasures.