Its a ero-manga called Rose x Mary (???×???) from what I can find, it seems pretty good. Its published in the bi-monthly mag "Comic Valkyrie" (which no one seems to scan, lol)
additional image
Is that some cute nun? lulz
Well nuns are supposed to wear black panties, so maybe.....
bump for sauce
>>858533heh, he already knows the source, just can't find scans apparently.
MOARRRR