Our current lifestyle necessitates the use of electricity. Electric current is often explained by comparing it to flowing water, but since electricity cannot be seen by the naked eye, this metaphor can be difficult to understand. What can we do to better understand electricity? Electricity is very helpful in almost every facet of our lives; it produces light, heat, and power. Even though we can see these benefits, we are usually unaware of electricity itself. However, if we simply learn the basics, we can get a clear picture of how electricity works. This book explains fundamental electrical concepts using a story told through manga followed by further explanations in written text. There are no complicated explanations— readers simply listen along with the heroine Rereko as her teacher Hikaru explains concepts. Even people who have had a hard time understanding electricity will find Hikaru’s explanations easy to comprehend. I am extremely grateful to Matsuda, who provided the artwork, and to everyone at TREND-PRO, who produced the book. I would also like to give my sincere thanks to Professor Masaaki Mitani for checking my work. I am also very thankful to Ohmsha, Ltd. for giving me the opportunity to write this book. I hope that in reading this book you will learn about electricity and gain a familiarity with it.