This week's Tokyoflash watch will certainly tickle the fancy of those who sleep with a set square beneath their pillow. The Kisai Polygon has a ring of triangles representing the hours and the nearest 10 minutes, with the individual minute being shown as a single digit through the middle. If you'd like to indulge in some retail therapy, you can take advantage of the company's pre-sale. Available in black, mirror, blue or pink, it'll set you back $99 (€77, £61) until Thursday, after which it'll cost $129 (€100, £80). Fancy learning how to read it from the team to built it?