The "Widow's Boarding House" series by Nikkatsu. All are independent productions that were directed by Shinya Yamamoto and bought/distributed as "Roman Porno." Two of these films are also a part of the "Semi-Documentary" series.
The Widow's Boarding House collection gathers 16 films released across 1974–1984. Below is every entry in release order, each linking through to its cast, crew and full details in LDB — the Loaded Database.
The Widow's Boarding House franchise in release order