When you first go to Shinwa, you get a "Start Quest" button and no back button. After you click "Start Quest", you get a link to the quest and a "back" link. I haven't looked at that "back" link yet. But after you've finished all of the quests, returned all the pieces of bracelet, you get a "Thank you" page with a "Back" button. The "Back" button takes you back to the start of the Shinwa quest. I think it would make more sense to be "Back to Sacred Lands".

And it should actually take you back to Sacred Lands, too. I agree with this.

Totally agree. Especially since if you visit Shinwa again, she gets all huffy about you showing up again. So I've come to just avoid the "Back" button because of that.

Back to Sacred Lands makes a lot of sense.

You know, I've never even noticed that button. Redirecting you back to the Sacred Lands would make total sense and should definitely be a thing.