To provide a highly convenient puzzle set, even if playing a written puzzle such as a crossword puzzle and a number place puzzle, producing no bits of eraser grit in correcting, after quickly erasing an intended portion, allowing rewriting on the erased portion and easily and surely erasing a wide area.

This puzzle set is formed of a puzzle of a type deriving a final answer by writing an answer to an illustrated question or filling a blank part, and a writing implement storing ink capable of vanishing color by heating. The writing implement stores the ink containing (a) electron donative color-forming organic compound, (2) electron-accepting compound, and (c) microcapsule pigment encapsuling reversible thermochromic composition at least composed of reaction media for controlling the color-forming reaction of (a) and (b) and changing chromatic color into achromatic color by heating.