Historical period drama is a film genre in which stories are based on historical events and famous persons.
 Some historical dramas attempt to accurately portray a historical event or biography, to the degree that the available historical research will allow.
 Other historical dramas are fictionalised tales that are based on an actual person and their deeds.
The revenge of the forty-seven "rōnin" (四十七士 , Yon-jū-shichi-shi , forty-seven samurai) , also known as the Akō incident (赤穂事件 , Akō jiken ) or "Akō vendetta", is an 18th-century historical event in Japan in which a band of "rōnin" (leaderless samurai) avenged the death of their master.
 The incident has since become legendary.
Eleven Samurai (Japanese: 十一人の侍 , romaji: Jūichinin no Samurai ) is a 1967 Japanese "jidaigeki" (period drama) film directed by Eiichi Kudo.
 It is also referred to as 11 Samurai.
 This is the third and final chapter in Kudo's Samurai Revolution trilogy.
 The plot is a samurai epic with a loose historical basis.
 "The young Lord Nariatsu was probably modeled after the real life figure of Matsudaira Nariyoshi, also known as Matsudaira Tokunosuke (1819-1839)," who was the 19th or the 20th son of the Shogun Ienari (1787-1837) and the younger brother of the Shogun Ieyoshi (1837-1853).
 "Nariyoshi died when he was 19 years old--a perfect fit for this story.
 The circumstances surrounding his death are obscure, which is also very convenient for dramatic purposes."
The Men Who Tread on the Tiger's Tail (虎の尾を踏む男達 , Tora no O o Fumu Otokotachi , alternatively They Who Step on the Tiger's Tail) is a 1945 Japanese period drama film, written and directed by Akira Kurosawa.
 It is based on the kabuki play "Kanjinchō", which is in turn based on the Noh play "Ataka".
The historical period drama is a film genre in which stories are based upon historical events and famous people.
 Some historical dramas are docudramas, which attempt an accurate portrayal of a historical event or biography, to the degree that the available historical research will allow.
 Other historical dramas are fictionalized tales that are based on an actual person and their deeds, such as "Braveheart", which is loosely based on the 13th-century knight William Wallace's fight for Scotland's independence.
Akō Rōshi (赤穂浪士 ) is a Japanese television jidaigeki or period drama that was broadcast in 1979.
 It is based on Jirō Osaragi's novel of the same title.
 It depicts the stories of the Forty-seven rōnin and Hotta Hayato.
47 Ronin is a 2013 American adventure drama fantasy action film depicting a fictional account of the Forty-seven Rōnin, a real-life group of masterless samurai in 18th-century Japan who avenged the death of their lord, in the style of "Chūshingura".
 Produced by Universal Studios, the film was directed by Carl Rinsch and stars Keanu Reeves and Hiroyuki Sanada.
History vs. Hollywood was a television show on the History Channel in the United States.
 On the show, experts are interviewed on the historical accuracy of a film that is based on a historical event.
 For example, the movie "The Last Samurai" was featured in one episode in which military historian Geoffrey Wawro, professor of history at the University of North Texas, and director of the university's Barsanti Military History Center, compared the movie with the actual events (December 2003).
 On the show the expert guests discuss the factual accuracy of the film as well as the everyday objects that a person of the particular time period would have seen.
 In some episodes an expert or the host will go on a journey to the actual historical sites depicted in the film, or interview someone who witnessed the event firsthand.
 In each of the more than dozen episodes both expert guests and filmmakers will discuss the historical accuracy of the film dramatized.
Reel to Real is an American television series on the History channel, hosted by Steve Gillon.
 "Reel to Real" shows a film based on a historical event, paired with a documentary about that same historical event.
 Historians debate the historical correctness of the film during the intermission.
 Films that have appeared on "Reel to Real" include "Battle of the Bulge", "Braveheart", "The Siege", "Bat 21", "Escape from Alcatraz", "The Last of the Mohicans", "Glory", "Unforgiven", "JFK", "Pearl Harbor", "Tobruk", "Pale Rider", "The Outlaw Josey Wales".
Masaki Kyomoto (京本 政樹 , Kyōmoto Masaki , January 21, 1959 –) is a Japanese actor, singer song writer, and guitarist.
 He has appeared in films and television series including "Legend of the Eight Samurai", "Sukeban Deka", "Kamen Rider Black", "" (aka "Ultraman Great"), "Cutie Honey", "Chage and Aska", "Ōedo Sōsamō", "Mito Kōmon", "Anmitsu Hime", "Food Fight", "Ultraman Tiga", "Ultraman Dyna", "Ii Hito", "GARO", 'Tenchu:Yamino Shiokinin" and most recently "81diver".
 He has performed on the soundtracks to "GARO" and "", performing the first two ending themes for the former, and producing GARO Project's performances of the final two ending themes for the series and the ending theme for the special.
 Masaki got a role in a buster film "Legend of the Eight Samurai" as Inuzuka Shino and it became a sensation that lead to Masaki's break out role "Ryu" on a popular Japanese period piece samurai drama series "Hisattsu shigotonin V" where he played Japanese obi-belt maker who is ex-ninja turned to be an assassin (shigotonin) to kill bad guys.
 He became a big star by that role and since then has appeared in numerous period piece drama series.
 He often plays a role much younger than his actual age due to youthful appearance.
 His picture with his son Taiga Kyomoto (Johnny's Jr.) went viral in Asia and many thought he is Taiga's older brother instead of father.
 He is an established musician as well produced sound track for TV shows and music for himself and other singers.

Question: What is the name of the Japanese Period drama based on the 18th-century historical event when leaderless samurai avenged the death of their master?
Answer: Akō Rōshi