I bought NTDOY from my brokerage account in US. I could, however, buy Nintendo from Japan's stock exchange from my other brokerage account in Hong Kong.
I guess you talk to your broker.
But, Holy cow, 7974 hits 71300yen!!! I am just speechless. NTDOY will be somewhere around 75-76. It could hit 80 as soon as tomorrow! And I WILL write to my cousin..LOL.