Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Columbia, Missouri to Osaka as you normally would.
Columbia Regional (COU) is the airport you will fly out of if you book a flight from Columbia to Osaka. You should not have trouble finding flights to Osaka from Columbia Regional; the airport handles an average of 0 outbound flights to Osaka per day. You should also have plenty of airline options to choose from since 0 airlines have flights from the Columbia airport to Osaka. It is only a 11.1 mi journey to Columbia Regional (COU) from Columbia’s city center.
Great question - COU to KIX just means Columbia Regional Airport to Osaka Kansai Intl Airport. Now you’ll know what these unique codes when you look for flights! Osaka Itami Airport (ITM), Kobe Airport (UKB) are some additional IATA codes for airports related to your trip.