The advantage of Osaka is that you never have to change hotels. Kansai Airport is about thirty minutes from the Izumisano area to the south, and central Namba or Umeda is roughly an hour from Ikeda and Ibaraki to the north, so you can play and still keep your evening plans.
Osaka has an unusual number of 27-hole clubs. Which nines your plan covers, and how they are combined on the day, changes the round noticeably, so it is worth checking the product page.
On spring and autumn weekends local Kansai demand fills the popular slots early. Summer favours an early tee, winter a later morning, and the drive out to the hill courses builds up traffic at commuter hours.
Comparing a Japanese tee time on the headline green fee alone tends to produce a different number at the counter. Confirm whether cart, caddie or self play, lunch, locker and the local golf tax are included, then check rental clubs or shoes, minimum player counts, two-player supplements, payment method and whether overseas visitors can book. Clubs may also specify check-in times, dress codes and bathing etiquette, so submit player names accurately.
Keeping one hotel in Namba or Umeda and playing two consecutive rounds in the same direction keeps transfers shortest. An arrival afternoon or departure morning leaves room for one more round near Kansai Airport.