Board Thread:News and Announcements/@comment-4698889-20180724122634/@comment-7342272-20180725220244

Considering the Evil's Theater memorabilia around them, the court stand right between them, and their darker clothes, I'd argue it's Hansel and Gretel (or "Arte" and "Pollo", same difference)

If not, then maybe just Kagamine Rin and Len in fancy outfits as a sort of callback to the original Evils Theater album.