Rent a car on Yonaguni island

How do I go about renting a car on Yonaguni island?

I'll be there on December 29th this year, for a full day. I'm coming in by air in the morning, and departing around dinner time.

I have found these two rental companies that offer at least some sort of online precence:
http://www.yonagunihonda.jp/
https://www.yonehama.com/

Yonehama says something about renting the car via the ticket purchase at JAL, I believe, or so Google Translate tells me. I've booked the ticket at JAL, but alas, not a word about Yonehama, or even about car rentals in general.

The former one, Yonaguni Honda, at least has a familiar name. Not sure if that means anything though. But that site too, offers the same challenge: it's all in Japanese.

I'm assuming on such a small island, they'd have a severely limited number of available cars, which means turning up unannounced might not be a good idea.

So what would be the best course of action?

I would try to write them an email. You could write a very easy email in English and then run it through google translate and send both the English and Japanese version. Google translate for Japanese is very bad. So make short very easy sentences. Nothing like “could you please provide information...” but more something like “Do you have a car from ... to ... What is the cost? “

Enjoy your trip to Okinawa!

The former one, Yonaguni Honda, at least has a familiar name. Not sure if that means anything though.

I think this is not a subsidiary of Honda (Car manufacturer) but a local dealer of Honda cars/motorbikes. Anyway you can use their reservation page.

http://www.yonagunihonda.jp/reserve/index.html

Most of them are also written in understandable English, but I will add something.

Reserved Dates are of course not when you reserve, but when you want to rent a car.
Pull down menu is only in Japanese, but you will be able to read numbers. 2018 12 29.

You don't need to write "assumed name".

Flight numbers are important information because they will pick you up at the airport for free.

You can enter text in the big text box, but as LikeBike wrote, write it simple.

After entering, you must check a "sending confirmation" box and then click "確認画面へ” button.

Thanks for the replies.

So I understand the gist is something like "give it a go, and see what they have to say" :)
I think I can manage that. One more thing: should I prefer one over the other, or does it not really matter? (other than pricing of course)

Just in case no cars are available, any advice on where to rent electric assist bicycles?

should I prefer one over the other, or does it not really matter? (other than pricing of course)

Honda provides more "English friendly" reservation page so I think it will be better. I have never been to Yonaguni so I have no personal experience though.

Just in case no cars are available, any advice on where to rent electric assist bicycles?

https://www.tanpoporyu.com/blank-7

This shop provides electric assist bicycles and it says "only one in Yonaguni island". You can contact via e-mail (I think e-mail address is not allowed to post here but you can find it on the page I posted).