spin-off; derived work
Refers to a creative work (film, novel, game, etc.) that is based on or branches off from an existing work, often focusing on a side character or setting. Cross-referenced with スピンオフ.
See also: スピンオフ
A spin-off of that popular anime will be released next year.
This novel was written as a derived work from the movie.
スピンオフ is a borrowed English term used mainly for TV, film, and business spin-offs, while 派生作品 is a broader, more formal native term for any work derived from an original.
Compound of 派生 (はせい, 'derivation') and 作品 (さくひん, 'work'). The term is a straightforward modern coinage for 'derivative work'.