Hagi, Tsuwano, Akiyoshidai

Hello JGuiders.
I read on the respective access pages for Hagi, Akiyoshidai and Tsuwano that visits to these places are often done in combination. Is that meant as being done in a daytrip or something? I mean, the transport times between the places seem a bit tough at times. Or is the bus (Bochi bus) convenient enough to make it a daytrip for all the places?

I will be on a JR pass by the way as I will do a lot of travel by shinkansen along the way. Is it worth taking the JR bus just to save the bus fare for Bochi bus? If only using JR bus and trains I suppose it would be too inconvenient, not?

I visited Tsuwano and Hagi using JR Pass. I did not use Bocho Bus, so I cannot comment on it. But if you have a JR Pass, it covers the JR Bus to Hagi, so why not utilize it? Some other pass issued by JR does not cover the bus, so make sure you have the right kind (e.g., the nation-wide JR Pass). There is no direct route between those places and takes too long to travel in ONE day trip, so it is better to split them in multiple days. One day, I took the steam locomotive from Yamaguchi to Tsuwano, the next day I took a JR Bus from Yamaguchi to Hagi.

I am planning to visit that area next spring so have no actual knowledge yet.

Other passes besides the nationwide pass do include the JR buses such as the JR Hiroshima Yamaguchi Area Pass.

As far as a day trip not sure what you mean - see all those places in one day? I am going to spend about five nights there but I am not in any rush. I don't think you could see that much in one day with all the traveling involved....

Those locations are done in combination due to the proximity to each other and the infrequent trains to the locations.

Getting to Akiyoshido/dai and seeing them (neither lingering nor rushing) will eat up a good portion of the day. I did it and by the time I got to Hagi, there was little time left that day to see much.
https://youtu.be/DqIKC9S8TFQ

I hit the main sights of Hagi early the next morning - even splurging on a taxi to get around, but it still took considerable time. I managed to squeeze in both Hagi and Tsuwano in a day, but I don't recommend it. I had to skip some places I still wanted to see in Hagi, and the Tsuwano Inari shrine is not a place you want to rush through.
https://goo.gl/uFKVHD

The Maria Chapel doesn't take much time to see, but getting there and back does a bit. The real issue is the infrequent public transportation. If you are renting a car, and also traveling during the months with more daylight, you definitely have a lot more breathing room.