A non-fiction brief history of Christmas and associated interesting problems. The author treated the subject as a simple historical event of his research object, so this book is not a religious book as its title might suggest. The first chapter focuses on discovering the origin of a Christmas celebration as a religious ritual. This simple task was involved finding answers to several important questions, such as when and where Jesus born? When and which church officials decided the date of Christmas? Did they select the correct date? If not, then what date and for what reason did they choose it? Once the first Christmas question is settled in chapter one, the following four chapters deal with the questions of when, where, and who did perform the first Christmas celebration in America. Again the simple inquiry leads us to a tangled web of the incomplete history of many earlier explorers and settlers. It includes the history of European explorers and their mutual conflicts in the period after the discovery of America by Columbus but before the Puritans' landing on Plymouth Rock. This book also describes Leif Erikson's North American settlement and related questions about its exact location. Probably the most intriguing subject is the possibility of pre-Columbian European settlers within the confines of the continental United States. Speculation about the existence of these unconfirmed settlements was triggered by the discovery of several rune-stones, which carried the inscription of rune alphabets, Norsemen's written language. In the last two chapters, the author describes the Japanese Christmas celebration as an example of Christmas in a non-Christian country. Since Japan is the author's native country, he has observed the evolution of Christmas there throughout the past sixty plus years since the end of World War II. It was refreshingly interesting compared to the traditional Japanese activities during the month of December.