http://www.businessweek.com/news/2014-02-03/nintendo-s-founding-family-to-sell-shares-as-buyback-terms-set
This seems to be the explanation for the buyback. If the Yamauchi family wanted to cash in their shares (and that certainly happens in 2nd and 3rd generation shareholders) Nintendo would be wise to make the purchase themselves via a buyback. Releasing 10% of the shares to the market in bulk would either tank the stock or invite a single shareholder to make a play for a large interest.
It's never ideal, but by having enough cash in reserve to make the purchase Nitnendo can do this without extra cost.
This seems to be the explanation for the buyback. If the Yamauchi family wanted to cash in their shares (and that certainly happens in 2nd and 3rd generation shareholders) Nintendo would be wise to make the purchase themselves via a buyback. Releasing 10% of the shares to the market in bulk would either tank the stock or invite a single shareholder to make a play for a large interest.
It's never ideal, but by having enough cash in reserve to make the purchase Nitnendo can do this without extra cost.