The Riemann expectation, like any other mathematical problems, is a very abstract problem in the world of math. Because of this, the Riemann expectation tends to become quite a difficult theme to discuss for those unfamiliar with mathematics. This social book puts the outline of the Riemann expectation in a compact manner, so it is easy to understand to the general public. This book also covers the history and drama behind his problem. The aspect of "prime numbers", which is said to be the core of the Riemann expectation, is written so that Junior High and High School students can understand. Skipping through the actual formula part will not spoil the mystical lure of the Riemann expectation.