You might have seen already the incredible street art by Julian Beever in the streets of the UK, art created with the technique of anamorphosis. This is a drawing style that when seen from a certain angle creates the illusion of vivid 3D images, even more when you consider they're applied to the streets and look pretty real. Japanese illustrator Nagai Hideyuki was influenced by Beever's work and decided to take a chance with this style on his own.
After a failed first try of drawing in the streets (it's illegal in Japan) he kept it personal by doing it in plain old pen and paper, which doesn't mean it's less impressive. Here are some examples of his amazing work: