Lower performance for exporters
The Japanese exporters are suffering from the Yen appreciation. The same sales as previous does not meet the profit up to now in Japanese Yen. In addition, the domestic products lose the price competitiveness and it gives the exporters sales down. To avoid the further Yen appreciation, some exporters shift their factories to overseas.
The Yen appreciation would associates the worse performance in exports sections and it would give the stocks market high pressure to sell the exports issues. The foreign investors would urge to take profit when the Yen value becomes weaker or the Japanese assets value is declining, and these actions stop the further Yen appreciation due to buying back the forex currencies against the Japanese Yen.
To be brief, the stock prices would go down in the phase of Yen depreciation while the stocks go up in the phase of Yen appreciation. As you can take a look at the charts of USD-JPY and Nikkei-225, those two factors are sure to show the characteristic nature of anti-relative movement.