So ... since Nintendo will not do the work to list on to the NYSE (Or any other exchnage not in Japan), Investment banks buy shares on the Nikki and then issue ADR on the US Pink Sheets. Nince Nintendo sells Their fine products mainly to the US, every time the dollar plunges the ADR and shares in Tokyo plunge.
Don't bother in trading on the Nikki.
Look for a good entry point and buy the ADR if you think Nintendo's lineup the coming holiday season looks good.