Parentheses seem like the best choice here, but I wanted to make sure as I couldn’t find any discussions of it or guidelines in the documentation.
2 Likes
Best choice probably, yes.
If there is an almost consistant use of something else like EM DASH for 昴 —すばる— that is shown prominently on singles, we can use it that too, IMO.
But it can also simply be part of the sort name, like I chose to do in 聖母たちのララバイ and many others.
There is no guideline, please ask question if you’re in doubt with some specific example. 
2 Likes