There is a secret reason behind each shape in these sudoku boxes. The shape in box 5 is missing and solvers must fill in this shape to start. [If you can't work out this part, check the video description for a spoiler.] Normal sudoku rules apply. On gold "entropic" lines, every three adjacent digits consist of a low (1-3), medium (4-6) and high (7-9) digit. Each purple "renban" line connects a set of non-repeating, consecutive digits (which can appear in any order). Solvers must determine the type of line in box 5 (renban or entropic). White dots join consecutive digits. Black dots join digits in a 1:2 ratio. Not all dots are given.