Man. Allow sombody with an MBA to step in here. First of all, depending on where Nintendo manufactures its goods, a weakening yen could greatly increase the cost of importing parts from foreign countries for manufacturing. If the manufacturing is done in Japan, this would be the case as they'd have to import parts from countries like Taiwan with a weaker Japanese yen.
In addition, a weaker yen makes it more difficult for Nintendo to cover ANY liabilities that it holds in foreign currencies. I imagine this is at least a fair percent of its overall debts, but I'm not completely sure.
Further still, Nintendo stock is near its 52 week low of 11.36 at a current price of 13.89 (http://finance.yahoo.com/q?s=NTDOY&ql=0). This is quite low considering that the stock is on an exchange that is currently at an ALL TIME HISTORICAL high. Also, the Nikkei is very high. Usually this type of positive investment sentiment would pull up the price of most stocks but securities that have a poor public sentiment, such as Nintendo, often don't benefit because peple are reluctant to buy them.
