And this isn't the first time I've seen someone "handcuffed with a red thread tied around the thumbs" in anime-style art; does it have some sort of cultural significance in Japan?
Appears to simply be a standalone pic, from what I see of this artist's gallery.
Let's see.If you manage to get yourself free, then I'll reward you with something.Although it's probably next to impossible untying your own thumbs.A good idea just came to mind.