Short answers, pulled from the story.
The Japanese asset price bubble began after five nations signed the Plaza Accord on the 22nd of September 1985. This agreement caused the US dollar to weaken against other currencies, leading to a rapid appreciation of the Japanese yen that triggered an export recession known as endaka fukyō.
The Bank of Japan cut its official discount rate from 5.0% down to 4.5% on the 30th of January 1986 and further reduced it to 2.5% by the 23rd of February 1987. The bank maintained this historic low rate of 2.5% for over two years between May 1989 and early 1990.
Land prices in Tokyo commercial districts jumped approximately 122% between 1985 and 1986. Average prices per square meter reached 4,211,000 yen by 1986 while prime areas like Ginza peaked at 30 million yen per square meter.
The Nikkei 225 index reached a record high of 38,957.44 on the 29th of December 1989. Stock trading volumes accounted for by corporations rose from 19% to 39% during the 1980s as cross ownership increased from 39% in 1950 to 67%.
Several major financial institutions collapsed including Sanyo Securities Co., Hokkaido Takushoku Bank, Yamaichi Securities Co., Long-Term Credit Bank of Japan, and Nippon Credit Bank. These failures occurred primarily between November 1997 and December 1998 when loan officers struggled to find profitable investment opportunities.
Japanese GDP in 2017 was only 2.6% higher than it had been in 1997 following the collapse of the asset price bubble. This stagnation led economists to label the era the Lost Decade or later the lost 20 years due to gradual economic effects.