From Aso-Kumamoto airport:
Take the express bus ‘Yamabiko’ from the airport. 2 hours ride brings you to “Taketa Onsen Hanamizuki” which is located just a few minutes walk from the station.
From Oita airport:
Take express bus “Air-liner” from the airport to the JR Oita station. Get off the bus at the Oita station to take JR train for Bungo-Taketa on Hohi line. If you take the express train “Kyushu Oudan Tokkyu” it will be less than an hour ride. If you take a local train, it will be around 90 minutes ride.