Oda Nobunaga (織田 信長,  Oda Nobunaga (help·info)^?, June 23, 1534 – June 21, 1582) was the initiator of the unification of Japan under the shogunate in the late 16th century, which ruled Japan until the Meiji Restoration in 1868. He was also a major daimyo during the Sengoku period of Japanese history. His opus was continued, completed and finalized by his successors Toyotomi Hideyoshi and Tokugawa Ieyasu. He was the second son of Oda Nobuhide, a deputy shugo (military governor) with land holdings in Owari Province. Nobunaga lived a life of continuous military conquest, eventually conquering a third of Japan before his death in 1582. His successor, Toyotomi Hideyoshi, a loyal Oda supporter, would become the first man to unify all of Japan, and was thus the first ruler of all Japan since the Ōnin War.

Oda Nobunaga was born on June 23, 1534, and was given the childhood name of Kippōshi (吉法師^?). He was the second son of Oda Nobuhide. Through his childhood and early teenage years, he was well known for his bizarre behavior and received the name of Owari no Ōutsuke (尾張の大うつけ^?, The Fool of Owari). With the introduction of firearms into Japan, though, he became known for his fondness of Tanegashima firearms. He was also known to run around with other youths from the area, without any regard to his own rank in society. He is said to be born in Nagoya Castle, although this is subject to debate. It is however certain that he was born in the Owari domain. In 1574 Nobunaga accepted the title of Kuge (or Court Noble), then in 1577 he was given the title of Udaijin (or Minister of the Right), the third highest position in the Imperial court.

Date Masamune (伊達 政宗^?, September 5, 1567 – June 27, 1636) was a regional strongman of Japan's Azuchi-Momoyama period through early Edo period. Heir to a long line of powerful daimyo in the Tōhoku region, he went on to found the modern-day city of Sendai. An outstanding tactician, he was made all the more iconic for his missing eye, and Date was often called dokuganryū (独眼竜), or the "one-eyed dragon".

As a legendary warrior and leader, Masamune is a character in a number of Japanese period dramas. He was played by Ken Watanabe in the popular 1987 NHK series Dokuganryu Masamune.

Date Masamune was the eldest son of Date Terumune, born in Yonezawa Castle (in modern Yamagata Prefecture). At the age of 14 in 1581 Masamune led his first campaign, helping his father fight the Sōma family. In 1584, at the age of 17, Masamune succeeded his father, Terumune, who chose to retire from his position as daimyo. The Date family was founded in the early Kamakura period by Isa Tomomune, who originally came from the Isa district of Hitachi Province (now Ibaraki Prefecture). The family took its name from the Date district (now Fukushima Prefecture) of Mutsu Province, which had been awarded to Isa Tomomune by Minamoto no Yoritomo, the first Kamakura shogun, for his assistance in the Genpei War (1180–85) and in Minamoto no Yoritomo’s struggle for power with his brother, Minamoto no Yoshitsune. Masamune's army was recognized by its black armor and golden headgear.

Sanada Saemon-no-Suke Yukimura (真田 左衛門佐 幸村, Sanada Yukimura^?, 1567–June 3, 1615 (Keichō 20. 5.7)) was a Japanese samurai, second son of the Sengoku period daimyo Sanada Masayuki (1544–1611). His proper name was Sanada Nobushige (真田 信繁), named after Takeda Shingen's younger brother Takeda Nobushige, who was a brave and respected warrior. He and his father were known as excellent military tacticians. Though their army was very small, they won many battles in which they were outnumbered. Sanada Yukimura was called "A Hero who may appear once in a hundred years" and "Crimson Demon of War", and the famed veteran of the invasion of Korea, Shimazu Tadatsune, called him the "Number one warrior in Japan" (日本一の兵^?).

He was the second son of Sanada Masayuki, his elder brother was Sanada Nobuyuki. He was married to Akihime (Chikurinin), a foster-daughter of Ōtani Yoshitsugu. They had two sons, Daisuke (Yukimasa) and Daihachi (Morinobu).

In 1575, the Battle of Nagashino claimed the lives of two of Sanada Masayuki's elder brothers. Masayuki, previously serving Takeda Shingen and Takeda Katsuyori as a retainer, inherited the Sanada clan and left for Ueda Castle. Yukimura also went, taking the Sanada name as well.

Honda Tadakatsu (本多 忠勝^?, March 17, 1548 – December 3, 1610), also called Honda Heihachirō (本多 平八郎), was a Japanese general (and later a daimyo) of the late Sengoku through early Edo period, who served Tokugawa Ieyasu. Honda Tadakatsu was one of the Tokugawa Four Heavenly Kings along with Ii Naomasa, Sakakibara Yasumasa and Sakai Tadatsugu.

A native of Mikawa Province in Japan, he lived during the Azuchi-Momoyama and Edo periods. Ieyasu promoted him from daimyo of the Ōtaki han (100 000 koku) to the Kuwana han (150 000 koku) as a reward for his service. In addition, his son Honda Tadatomo became daimyo of Ōtaki. In 1609, he retired, and his other son Tadamasa took over Kuwana. His grandson, Tadatoki, married the granddaughter of Tokugawa Ieyasu, Senhime. Despite his years of loyal service, Tadakatsu became increasingly estranged from the Tokugawa shogunate (bakufu) as it evolved from a military to a civilian political institution. This was a fate shared by many other warriors of the time, who were not able to make the conversion from the chaotic lifetime of warfare of the Sengoku period to the more stable peace of the Tokugawa shogunate.

Ken Watanabe (渡辺 謙, Watanabe Ken^?, born October 21, 1959) is a Japanese stage, film, and television actor. To English-speaking audiences he is known for playing tragic hero characters, such as General Tadamichi Kuribayashi in Letters from Iwo Jima and Lord Katsumoto Moritsugu in The Last Samurai, for which he was nominated for the Academy Award for Best Supporting Actor. Among other awards, he has won the Japan Academy Prize for Best Actor twice, in 2007 for Memories of Tomorrow and in 2010 for Shizumanu Taiyō. He is also known for his roles in director Christopher Nolan's Hollywood blockbusters Batman Begins and Inception.

Watanabe was born in Koide, Niigata prefecture. His mother was a school teacher and his father taught calligraphy. Ken has two children. His daughter Anne Watanabe is a model.

After graduating from high school in 1978, Watanabe moved to Tokyo to begin his acting career, getting his big break with the Tokyo-based theater troupe En. While with the troupe, he was cast as the hero in the play Shimodani Mannencho Monogatari, under Yukio Ninagawa's direction. The role attracted critical and popular notice.