We've scanned every flight from Manila 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.
Osaka Kansai International Airport is just one of the airports in Osaka. If you're not set on a specific airport, try changing your search from Osaka Kansai International Airport to Osaka to see a broader range of flights – they might be cheaper.
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.