I don't know why I wrote "12" but one of 18 different mini airplanes comes with the can and it's been available since last week. They will end the campaign once they are out of the toys. The larger airplane models (ANA's 787 is the most popular one) comes with two cans of coffee. Ergo, the mini plane is 120 yen and it's 2 inch long and 2 inch w. The larger one is 240 Yen and it's like 3 inch w with 5 inch l.

Unfortunately, not every convenience store sells coffee with toys. Some stores sell it without them. However, if you try several convenience stores, I am sure you will see some. I have seen Family Mart (One of the convenience store chans) usually has them but there is always an exception. I am sure these will be avialable on Yahoo Japan auction site later but don't exepct them to be so reasonable