Travel from Oita to Kyoto

Can someone help me on how is the best way to travel from iota to Kyoto? is there train going there? Or I have to fly?

There are trains of course, though since you need to make a large détour via Fukuoka, use them only if you have plenty of time. Flying is another option, the low-cost carrier Jetstar has flights to Kansai airport (and ANA and JAL to Itami). There are also ferries, but I am less familiar with them, you can Google "Oita Osaka ferru".

I meant "ferry", of course.

Beppu and Oita are pretty close, so this access page basically covers the options:

http://www.japan-guide.com/e/e4705.html?aFROM=2158_4700

Note that train is probably the fastest, cheapest (with a JR Pass) and most convenient once you factor in travel to airports or ferry terminals.

Thank you...let me research more

Note that train is probably the fastest, cheapest (with a JR Pass) and most convenient once you factor in travel to airports or ferry terminals.

The only count on which you are correct is "cheapest" (with a JR pass). It's certainly not faster, as you could see if you just did the math instead of speculating. And it's only more convenient if you are super lazy and just want to get your butt on a train (and even then, you have two train changes, at Hakata and Shin-Osaka).

As for me, spending four hours trapped in trains is a no-no if I can avoid it. I much prefer one hour in a plane and one in a train. At least the rest of the time I can walk around.

Not sure why you feel the need to be so hostile. My general recommendation is based on actual calculations. I do think the comparison is close enough that the best method probably depends more on personal preferences than straight numbers, however I also think that the average traveler is better off taking the trains over flying. Let's take a look together:

Depending on the ultimate destination in Oita, trains take about 4-4.5 hours and involves up to two relatively easy transfers.

Plane involves the Haruka Ltd Express (70 min) to KIX
Base on KIX recommendations you should check in minimum 15 mins early (add 15-20 mins if using Terminal 2 since you need to transfer by shuttle bus)
Check-in and Security procedures
Flight time about 1 hour
Deplane, get luggage, transfer to bus 10-20 mins
Transfer to city 30-60 mins depending on destination
Total 3-3.5 hours minimum but realistically more like 4+ hours for the average person.

Ferry takes about 13 hours and is not advised unless you have a particular interest in ferries or the Seto Inland Sea.

So yes, travelling by plane is faster on pure travel time. But there are other factors, like realistic transfer times, transferring between multiple modes of transport and the possibility of flight delays that make predicting actual travel time harder to generalize.

Cheaper is also hard to generalize since there are discount flights (that may also affect travel times) to consider and various rail passes (that also affect travel times) that change the math. On pure cost, flying will be cheaper than train but also likely slower and even less convenient due to having to fly via LCC.

Train is definitely more convenient considering the transfers are far easier and there are no check-in/security procedures.

So yes, I still recommend train over flying unless you already have a preference to fly. And let's be honest, more travellers are coming to Japan with an interest to take the shinkansen than care about flying especially when they are so comparable as in this case.

I suggest train, change at Kokura, since all train stop here.
Try using Hyperdia to find exact time.
It only require 1 change and just over 4 hours. I would say it be faster and less moving about on train then aeroplane.

Thank you for your suggestion. I am looking into it now. My purpose is to see autumn leaves between mid to end nov

If you have time, take the overnight ferry across the inland sea. It would be a lot more interesting than plane or train

https://www.ferry-sunflower.co.jp/language/english/