About this, I bought some LDs from them after christmas and I had the same problem: Surugaya's products were not listed in the search. I could find their store but not browse it.
However, I managed to actually order through a work around.
If I viewed their store on Japanese Rakuten (by changing my language in the top right menu), which I tend to do sometimes anyway because babelfish english, things I've looked at would show up under "recently viewed" on the Rakuten international main page.
And thus I was able to add things to my cart and check out. Just thought it was a listing error, not that they stopped :/ They didn't tell me that in their mail contact with me during the purchasing process either.
And I got my things as well.
Bummer though, they're pretty much my go-to store for LDs and other obscure crap.