Recommendations for Shikoku

We will be driving from Matsuyama to Naruto to see the whirlpools which is a 2-2.5 hour journey in mid Jan. Since we do not have to arrive until 4pm for the whirlpool sighting, I can stopover at a place of interest in Shikoku. Iya Valley interests me for the scenic beauty but I think it will be snowy and cold so it may be a challenging visit.. I will be grateful if japan-guiders can suggest other places of interest on my way near Shikokuchuo, Miyoshi or other places along the way.
My colleague mentioned seeing in a TV program of a origami museum in Shikoku? Any idea of the location?
Thanks!
SG

Well, if there is snow in iya valley I would also avoid to take the toad through central Shikoku and stay in the coast, driving through Takamatsu.

Possible sightseeing spots on this route are:
- garden in Takamatsu
- Kotohira
- some of the 88 temples of the Shikoku pilgrimage
- or simply a stop in a day spa on the way

I would also calculate a bit more time for the drive, as you will want to be at Naruto at latest by 4, as it will start to get dark quite soon after (probably around 5, with maybe sunset at 17:30, depending on the actual day you go). So from that perspective I would schedule the additional sightseeing close to Naruto.

Enjoy your trip to Shikoku!

Thanks LikeBike for your advice!

If you can find time in your itinerary to visit Iya Onsen overnight, you really should. Hotel Iya Onsen was a very valid splurge in my opinion. But yes, as LikeBike said, avoid the central road! I can confirm the snow on that mountain route is problematic 😂

The castle at Marugame is worth visiting as well.

I presume you'll be sticking to northern Shikoku.

There is Imabari Castle, which is a nice seaside castle. There is also the Marugama castle in Kagawa.
The half day hike up to Konpirasan in Kotohira is one of the best you'll ever take.
https://youtu.be/ley9rVIewoQ

Also if you're driving, it's ideal since you can easily go to Unpenji in Kanonji City, Kagawa, one of the very best temples of the Shikoku pilgrimage.
http://www.shikoku-cable.co.jp/unpenji/tera.htm

And as mentioned, the Ritsurin Garden in Takamatsu is one of the finest in Japan.
https://youtu.be/afx-Ju52FiY
It's not as good in winter, but there are many pine trees which don't mind the cold.
Lastly, Yashima was great to see too - the view from the top over the Inland Sea was terrific.
https://youtu.be/EQgQ9V3qk38

That should give you some ideas.
I hope you see as many as you can, because really, driving all the way across Shikoku just to see Naruto just isn't worth it.

How about Saijo city for free Asahi Brewery tour, and free beer?
https://www.asahibeer.co.jp/brewery/shikoku/