I’ve had the same issue. I’d like to support the artists, but the music is only available as physical media or for streaming on sites I can’t use or don’t want to give money to.

My current plan is to support them by buying unrelated digital merch, such as voice packs. Though if too many people do this it will distort with their metrics, so it’s not a great solution.

I bought some cds from CDJapan.

I’ve bought some of Hololive’s stuff on qobuz.com, where I buy most of my digital music. You just need to search for the Japanese name. Seems like they have stuff from Miko, but not her newest album. They’ll probably have it a little later though.

With money