What is "gaiden"

is a Japanese-language word meaning " side story" or "tale", used to refer to an anecdote or supplementary biography of a person. The use of gaiden is commonly used in popular Japanese fiction to refer to a spin-off of a previously published work that is neither officially considered a sequel nor a prequel. However, some gaiden are retold stories in the perspective of a different character, similar to that of a flashback.

Works that include the use of the word gaiden in their titles include Fire Emblem Gaiden, Ten no Haō Hokuto no Ken Raō Gaiden (spin-off of Fist of the North Star, which is told through the eyes of Kenshiro's brother, Raoh) or Albert Odyssey Gaiden (released in English as Albert Odyssey: Legend of Eldean). The word gaiden has been used in English titles as well, such as Ninja Gaiden (literally "Ninja's Tale", the American title for the Japanese series Ninja Ryūkenden) and Resident Evil Gaiden (a European-developed spin-off of the Japanese Resident Evil franchise), Super Robot Taisen Alpha Gaiden, which tells a future that would happen without the heroes fighting at the time of need as well as Barkley, Shut Up and Jam: Gaiden (an apocryphal epic detailing the canon account of Charles Barkley, who revives the condemned culture of b-ball to save Neo New York and his son Hoopz from the machinations of the traitor Michael Jordan). The Legend of Zelda: Majora's Mask was called Zelda Gaiden resp. "ゼルダの伝説 外伝 （仮称）" (Zeruda/Zelda no Densetsu: Gaiden (Kashô)) in its development stages.

Films such as Battle Royale use the term Gaiden to refer to supplementary or additional works.

In anime, examples include Darker Than Black: Gaiden, an OVA released as a prequel to the events of the second season of the show.