Of course it's shopped. It came from a shopper's board originally.
If you think Ishikei did this I think you'll have to provide some proof. It's not on his site, it's not in his doujinshi. Unless you think he posts on imageboards?
but there's no sign of it being shopped at all in this picture though. and aside from that theres no source linking it to that shoppers board your talking about.
You're right. It's not shopped. It's GIMPed. "Software used: GIMP 2.4.2" it says in the JPEG comment. Ishikei uses Adobe Photoshop CS3 though (just check any pics on his site).
Either way it's an edit NOT done by Ishikei. So I'm adding the tag again.