This book explores how mathematics appears in everyday life. It presents math in a fun and beautiful way using knowledge at the junior high and high school level. It is written for general readers, not for experts. The book avoids difficult math and instead focuses on how new ways of thinking and careful observation can reveal interesting math ideas. It is divided into 33 topics. These include familiar recreational math like tournament games, magic squares, and math tricks, as well as unique ideas like the geometry of origami and toy train tracks. Some of the topics in this book may be unfamiliar to readers outside Japan, as they are based on things the author has observed in daily life in Japan. However, this is also one of the unique features of the book. It offers readers a glimpse into everyday life in Japan. The goal is to help readers feel closer to math, rather than to provide deep academic content. Features Easy to understand with junior high or high school level math knowledge. Introduces math found in real life, like origami. Includes many topics based on the author’s popular social media posts (over 23,000 followers on X). Connects math topics with hands-on activities and experiences. Helps readers see the world in a new way through a "mathematical way of thinking". Focuses on intuitive and visual understanding, not difficult formulas or theories. Provide links (with QR codes) to puzzle apps developed by the author.