We've scanned every flight from Cardiff to Osaka to find the best deals. If you want a cheap flight, it's best to be as flexible as you can on dates. If that day's no good for you, try searching by month to see some alternative dates.
You can use the filters on your search to see more flights and find cheaper rates – Osaka has more than one airport. So if you don't need to fly into Osaka Itami Airport, it's worth checking your other options.
If you're planning on going to Osaka during this time, you could take a look at other airport options. Or you could try to get a last-minute bargain.