If you don’t have specific dates for when you'd like to fly to Osaka, try searching by month. It's also worth looking out for flights with Etihad Airways, as their fares are normally the best-value.
To find the best deal, why not look at other options in Japan? Some other cities may have cheaper options for flights and accommodation.
When it comes to getting cheap flights to , the most important thing is to book in advance. Bargain deals and last-minute offers for Osaka do crop up, but you'll have to be flexible to get them. If you want to fly at a specific time, it's always best to book early. The same applies to hotels – the earlier you book, the more choice you'll have.