How did Japan get so much in debt?

They like government-sponsored projects too much -- all the high-speed rails and highways and bridges, as well as nuclear industry. Also, it started with stimulus after property bubble collapse in early 1990's.

Their debt accumulated during the 1990's (the lost decade), it has nothing to do with Fukusima or nuclear bombings.

I think it's partially to do with the Tsunami that happened 2 years ago. They had a lot of rebuilding to do and I think that took a big chunk of the money from the economy.

Cause American dropped two nukes on them and cleaning up all that sh*t cost money.