Japan's real estate bubble crashing had nothing to do with deflation. The claim that it did, is one of the greatest myths in all of economics. They've had zero net deflation on their consumer price index since ~1989.
The US dotcom bubble imploding was also not deflation.
Japan got a real estate bubble from extreme monetary expansion flooding into the economy in the 1970s and 1980s. They got a popped bubble when that fake economic party ended with monetary expansion falling to single digits in the early 1990s. The reduction in that rather massive monetary expansion forced their economy back to reality.
The US real estate bubble occurred in part for the same reason. The Fed juiced the economy after 9/11 to attempt to avoid a recession.
When reality hit, Japan shifted to accumulating vast amounts of debt to fake a better economic condition than what they really had. That overwhelming debt has continued to drown their prospects as the years go by, sapping growth potential.
You can see this same exact scenario playing out in China right now.
A bubble imploding is not deflation, just as price contraction on the CPI is not inherently deflation.
See: flat screen tv prices, computing prices, etc. The US enjoyed decades of general price stability and contraction due to vast automation and economies of scale after the civil war, none of which was deflation (monetary contraction).