Japan - suggestions for a last minute change of plans?

We were planning on staying in Hiroshima for a day next week before biking the shimanami kaido and then heading to Osaka, but the weather forecast isn’t promising so we’re looking to pivot.

We currently have a hotel booked in Imabari - is it worth going there if not for the ride? It’s refundable, so we’re not committed to going there. The hotel in Hiroshima that we’re at the night before is booked up already, so since we’ll have to move at least hotels, is there any cool place that’s worth the day?