A chart of the Nikkei index since 1970, of the BoJ prime rate for the same period and the Yen vs US$ might be a helpful start. Below is some timeline information:

Here is a chart of the Nikkei:

Feb 23, 1986 - Two of the other five newly admitted firms are US securities companies, Morgan Stanley and Co. and Goldman, Sachs and Co. The remaining three, Vickers Da Costa Ltd., SG Warburg, and Jardine Fleming Holdings Ltd., are British.

Feb 14, 1986 - As an exchange member, it will no longer have to pay commissions to Japanese traders. Goldman, Sachs; Morgan Stanley and three British securities firms will all begin trading on the Tokyo exchange in the next few months.

Apr 5, 1987 - Fueled by investments from Japanese banks, insurance companies and securities firms--some the largest in the world--Japan has become the biggest foreign holder of US debt. Moreover, its direct investments range from Sumitomo Bank's $500 million participation in Goldman, Sachs & Co. ...(Prevented by law from exercising voting rights in Goldman.)

Aug 16, 1989 - TheVfall Street Journal, reported on Aug. 16, 1989, that Salomon Brothers, Merrill Lynch, Goldman Sachs, and Morgan Stanley Japan Ltd. are doing well in Japan, but "on the whole, foreign losers vastly outnumber the winners.
 

"It is not necessary to have hope in order to persevere."