companion volume; sister volume; sequel
Refers to a book, film, or other work that is related to another as a companion piece or sequel. Often used in publishing and media contexts.
This novel was written as a companion volume to the previous work.
A sister film is scheduled to be released next year.
Compound of 姉妹 (sisters) and 編 (volume, edition), literally 'sister volume'. The term is a straightforward modern coinage without a complex historical derivation.