Absolutely, I can recommend the place wholeheartedly: https://rb-fullthrottle.com/english/rental-index.html

Communication in English over email was quite fine. The owner doesn't really speak English but is very happy to make it work with a translation app. The shop is actually one stop down the north Shikoku train line, but they have a deal with a parking garage in downtown Takamatsu, happened to be very close to my hotel. He was there to deliver the bike at the prearranged time and go over the paperwork etc., and said I could just drop off the bike any time I wanted on the last day and give the keys to the parking attendant.

I'd rented a Kawa Z900RS Cafe Racer a few days earlier in Tokyo for a trip to the Izu peninsula with a local friend, and it was quite funny that the word in Japanese for the best grade of petrol is "hai-occu" - high octane - but it sounds like "hayaku" - hurry up! - so it felt quite rude to just say that to the gas station attendants when we stopped to fill up! Luckily the 250 took regular.

EDIT: Might as well mention my route, which I think is a fine two-day itinerary. I started south on route 438 to the Mount Tsurugi chairlift - about three hours, starting on calm country roads and then getting into some twisties - took the chairlift up and hiked to the peak of the mountain, took the back path down. Then headed west to Oku-Iya vine bridge - there is an entrance fee, and you can ride a wooden cart suspended across the river, although it was closed for repairs when I was there. So I continued to the Scarecrow Village - you can see most of it from the road, but I think there are a few accessible buildings including the old school - then on to Ochiai Village (aim for the observatory on the small road south of the river, rather than the main road or the village itself). Then went on to Iya Kankyo Ryokan - very reasonable rates for a Japanese-style single room and breakfast, big parking lot right across, and it was within walking distance of the Higashi-Iya Vine Bridge. It was closed by the time I got there, it was starting to get dark, so I just walked around the area without crossing the old bridge itself - glad I got to do it earlier with the other bridge!

Next day I went a bit further south down the Oboke Gorge to a place called Happyraft for some whitewater rafting. It was very fun and we absolutely did flip the raft on some rapids. Afterwards I went back up via the Old Route 32, the slowest national highway in all of Japan, past the Statue of the Peeing Boy - definitely worth stopping for a photo! - and then a late lunch in a grandma-run home cafe. That left me just enough time to rejoin the main road 319 back up to Takamatsu, drop off the bike, pick up my luggage and catch the next-to-last train west to Matsuyama.

I also have to say that Takamatsu town itself is very much worth a visit! It has one of Japan's top three public gardens (very affordable and infinitely less crowded than the other ones in touristy cities!) and Yashima mountain just east of the city center, an awesome hilltop plateau with an important place in Japanese medieval history. I would have definitely liked to stay in and around Takamatsu longer if I'd had the time.

I remember your trip now.

The ADV150 is highly underated IMO. I had a very abused one in Java and loved it.

October / November are good times for southern Honshu/Shikoku/Kyushu I reckon.

I didnt know about full throttle rentals ( https://rb-fullthrottle.com/english/rental-index.html )

Damn good value.

AnTyx,

Thanks for the info. I have bookmarked the shop for my future use.

Japan is indeed a great place to tour on a bike.

So many places still to visit in Japan that I have hardly scratched the surface. However it is on the expensive side for me for the accommodation and bike rental as I am from a developing country and currency is weak.

I have considered buying a bike in Japan and keeping it at my brother's place to save the bike rental cost over the long term but his home is so tiny that it barely fits his mini car and I don't want to inconvenience him.
And I have not even taken into account the insurance and other legalities to keep the bike on the road. So even if i could keep the bike in Japan I have not done the sum to determine if it is worthwhile.

HomersGSA,

Yes, I agree. Bloody good bike it is the Honda ADV150!
I did have a small annoying thing with the ADV150. Whenever I let go of my hands from the handlebar, it would wobble like it had a tank slapper.

I texted the bike rental and was told that they said it is happens on the ADV150 for some reason. They have 2 units and both have this wobble. Just told me to not to ride hands free. LOL

Yes, October/November is a good time for Honshu region with very pleasant weather but I will need to make sure I layer up enough and will need a true winter glove. I only used a Astars mid season WP glove and I wish I had heated grips and/or a handguard to block the wind!