Japan had the will to fight by means of brute manpower, but not this kind of technology.
They were working on it and they had others.
They were planning in the fall of 45 to start spreading weaponized plague to the US and Australia.
Considering how transportation was in those days with people flying off to Europe and the Middle East it would have gone global in weeks if not days.
You want horror? Think of war torn Europe being hit by the Black Death on Steroids.
It would have made the 1919 Flu Epidemic look like a cold.
“Japan had the will to fight by means of brute manpower, but not this kind of technology.”
Japan, the Army and the Navy, tried to build atomic bombs to use against the United States, but failed to do so before conventional B-29 bombardment raids destroyed part of the atomic research facility at the Rikken laboratories and the later atomic bomb attacks destroyed Hiroshima and Nagasaki with more such atomic bombardments being threatened. Japan also built some super-submarines in part to transport atomic bombs into U.S. harbors and anchorages. So, Japane did have and almost have the technology to necessary to build most of the atomic bomb, but they were stopped short of their goals when the United States delayed Japanese research with air bombardments, seized German U-boats transporting German Uranium stocks to the Japanese, and completed the atomic bombs before Japan could do so.