Koya San heritage ticket from Kansai?

I will arrive at Kansai airport on Thursday morning at 9:00
I will then continue traveling to Koya San but was wondering if I can buy the Koya San Heritage Ticket directly at Kansai Airport or should go to Namba first with a single ride ticket and buy the heritage ticket there?

Also I read it is valid for 2 consecutive days
But I will stay for 2 nights
So I have
1. Day of arrival
2. Day in Koya San
3. Leave Koya San

Will I still be able to use the heritage ticket to get back to Namba?
Does it work on a 24 hour basis? (so if I buy it on day 1 at 10:30 am, can I then use it untile 10:30 am on day 3? Or is it only valid on exact dates? )

I don't know if it makes any sense to buy the Heritage ticket if my return trip is not covered by it

2 calender days as per ticket website.

you'll need a separate ticket to get to namba on your first day.

So you're staying two nights at Koyasan? In that case, the World Heritage Pass wouldn't be a good choice, as it is only valid for two calendar days as the above reply says.

I believe you can only purchase it at Nankai stations in Osaka.

Sorry I misunderstood you question. I thought you were at Nanba the first night.

If going to Koyasan for 3 days, 2 nights. then purchase a 3 day Kansai Thru Pass fopr 5,200 yen.

Okay I figured the Hermitage pass would Maybe not of that much use

Kansai through pass Will also give me access to the Koya SAn bus then?

Thanks for the help :)