The Prologue lets the audience know that the author, Kokichi Katsu, is writing this book in retirement. He has formally put his son, Rintarō, in charge of the family as the man of the house. His daughters are doing well by taking care of all the domestic issues. Thanks to the children, Katsu and his wife have a comfortable retirement.

Katsu has spent the past year confined to his house, as ordered by his superiors. During that time, he focused on reading different types of texts, for instance, those about war. He realized that even the most illustrious historic personalities, such as military leaders, often forgo the laws of Heaven. Eventually, this behavior catches up with them, and they pay for their disregard dearly. Therefore, Katsu wonders how he has been able to avoid this fate. Perhaps, he had been blessed by Heaven, the author concludes. He is open about the fact that he has led a less-than-honorable life. Katsu has never held a government office despite being a hereditary samurai. The author is also aware that many people dislike him because of his misdeeds. However, he is free of regret.