Ten Hours, One Piece of Paper
What could you do with 10 hours and one piece of paper?
Satoshi Kamiya (at first I wondered whether this was his real name) would fold the paper 1361 times and come up with this.
I wondered whether that was his real name because “kami” means paper, so it just seemed a little too convenient. However, this wikipedia article seems to confirm that it is his real name (of course, the kanji for “kami” does not mean paper in his name).