Yoshihito, posthumously honored as Emperor Taishō, was the 123rd emperor of Japan, reigning from 1912 until his death in 1926. His era, known as Taishō Democracy, marked a liberal and democratic shift in domestic political power. He navigated Japan's participation in World War I, the Spanish flu pandemic, and the Great Kantō earthquake of 1923. Born to Emperor Meiji and concubine Yanagiwara Naruko, Yoshihito became crown prince in 1888. His reign was marked by neurological issues, limiting his involvement in politics, and his eldest son, Crown Prince Hirohito, succeeded him. Despite health challenges, Yoshihito received tutoring in various subjects and showed interest in western culture, languages, and military concerns. In 1900, he married Sadako Kujō, and the couple had four sons. Yoshihito's reign left a significant impact on Japan's political and historical landscape, shaping an era of change and challenges.

Joshua Abraham Norton, also known as Emperor Norton, was a notable figure in San Francisco during the 19th century. Born in England and raised in South Africa, Norton arrived in San Francisco in 1849. After a brief period of success, a business venture led to bankruptcy in 1856. In 1859, he proclaimed himself "Emperor of the United States" and later took the title "Protector of Mexico." Despite holding no formal political power, Norton was treated with respect in San Francisco, and currency issued in his name was honored in some establishments. Often considered eccentric, he was a beloved figure in the city and received various favors from friends and sympathizers. Norton's unique story has inspired literary characters created by renowned authors such as Mark Twain, Robert Louis Stevenson, and Neil Gaiman. His reign as "Emperor" and his impact on San Francisco's history have made him a fascinating and enduring figure in American folklore.

Emperor Ninkō, posthumously known as Ayahito, was the 120th emperor of Japan, reigning from 1817 until his death in 1846. His rule witnessed the decline of the Shōgun's power, exacerbated by natural disasters, corruption, and Western interference. Despite efforts to revive court rituals and practices, including the establishment of the Gakushūsho for the Court Nobility, Emperor Ninkō faced challenges such as the Tenpō famine and a revolt in Osaka. His reign marked the beginning of the Bakumatsu period, leading to the end of military government. Ninkō's family included 15 children, but only three survived to adulthood, one of whom succeeded him as Emperor Kōmei. His mausoleum is located in Sennyū-ji, Kyoto, alongside other imperial predecessors. The eras during Ninkō's reign were Bunka, Bunsei, Tenpō, and Kōka. His family lineage comprised seven sons and eight daughters from various concubines. Emperor Ninkō's life and reign hold historical significance during a transformative period in Japanese history.

Emperor Reigen, also known as Satohito, was the 112th emperor of Japan, reigning from 1663 to 1687. He was the 19th son of Emperor Go-Mizunoo and had a large Imperial family, including 13 sons and 14 daughters. His reign saw significant events, such as the establishment of courts of inquisition throughout Japan to eliminate vestiges of Christianity and the preservation of Hokke shu Buddhist religious practices. Posthumously honored as Emperor Reigen, his name was created during the Meiji Era by combining kanji from the names of two previous emperors. His ascension to the Chrysanthemum Throne followed the abdication of Emperor Go-Sai. Emperor Reigen's life and reign are significant in Japanese history, contributing to the cultural and religious landscape of the time.