Shikoku car rental: avoid doubling back?

I am wondering if I am attempting the impossible.
I am putting together an itinerary on Shikoku for 3 weeks in October.
We arrive at Tokushima, and will be leaving via the port at Matsuyama.
Seems like it will be easiest if we just 'bite the bullet' and hire a car for the whole 3 weeks.
Do you know of any company that has a moderate fee to drop the car off at a different location to where it was collected?
I can't see any other option than driving the rental back on the Expressway to Tokushima, then catching hopefully an Express bus back to Matsuyama...taking the best part of a day out of our itinerary.
I'd pay NOT to do this, but only if the extra cost was something in the range of moderate or reasonable.
Any ideas??? Thank you so much in advance :-)

Did you check what the price is for the ETC, gasoline and train ticket to drive back vs the drop off fee?

Thanks for your input LikeBike. Yeah, all of those things are a consideration but our itinerary is packed so tight (nothing locked in yet) the main down-side to me is it will take out the best part of a whole day to return the car to Tokushima from Matsuyama and then return to Matsuyama Port. That's super expensive in my mind!

What I have re-worked this morning is...we are flying into Osaka, catching an Express Bus to Kobe for 2 nights and then we WERE going to bus from Kobe to Tokushima to start our 3 week approx road trip around Shikoku. Final destination is Yamaguchi Pref to see friends, so we were going to take a Ferry from Matsuyama to Yanai. That's why there is the problem with returning a car that we hired in Tokushima!

So...it seems to work not too badly by us catching an Express bus from Kobe later in the afternoon (visiting the Kobe Earthquake Institute and Museum in the morning) and then catching a bus all the way through to Matsuyama....arriving round 8pm. Big day, but a little pain at this point will help us avoid a big pain in the neck almost 3 weeks later when we are leaving for Matsuyama Port and need to get rid of our rental from Tokushima.

If we approach it this way, there are other pluses in my mind. I always imagined starting in Shikoku at Matsuyama. And then it seems relatively easy to do a clock-wise circuit of Shikoku..spending time in Takamatsu / Shado / Tokushima / Iya Valley and Mt Tsuguri / Kochi / Yusuhara and Shikoku Karst / Shimanto River / Uchiko / Ozu / Mt Ishizuchi and home to Matsuyama. Roughly in that order...more or less :-) Any comments and suggestions welcome

Best to check the fee first, before going any further.

I'd guess it will be similar or less than the extra fuel, tolls, tickets, time and effort from Tokushima.

Such a simple statement by guest H..."Best to check the fee first, before going any further." on this thread...but so very helpful! Thanks so much.

I did triple check all of the car rental links on this website and in the end it really comes down to Orix.
The interface on their website works so smoothly and the option of a different drop off point compared to the pick up point is easy to choose. I am not a web designer, but it proves to me that if a company has a well-designed functional website, it will increase sales out of sight...rather than a clunky, user-unfriendly interface for your clients. Plus the complication of needing to be user-friendly in at least 2 languages must make the website design of a Reservation System trickier? Whatever web designers charge for their fees, if they do a good job, they deserve a bonus in my book.

Anyway, all I need to be sure of now is:

Is it common practice for rental car companies to have their vehicles go on a Car Ferry to Shodoshima...or is that a no-no?? Any comments would be super handy...before I try and call or email Orix in Tokushima :-)
Thanks in advance again.

https://www2.tocoo.jp/en/ I've had good experiences with ToCoo for car hire in the past. They give prices for a number of hire companies, have good English-speaking support, and clearly show the "drop off" charge (i.e. the charge you pay for picking the car up at A and leaving the car at B).