You can catch a last minute plane but it'll cost loads more than what you probably have in mind (or maybe not, since Singapore -assuming that's where you're leaving from) is not all that far from Japan. As for booking an airline ticket not being 100% sure you're gonna be able to get on that plane... I wouldn't do it, though you can always resell it (the airline company itself makes sure it is resold) but you'll still lose money. As for the low cost flights... I know some European ones but I don't think that'd help much xD
Have fun on your trip!!
