Several of the series' games' story have been adapted into original video animations, novels, or manga.
Starting from Memories Off 2nd, all main series games offer the possibility of multiple endings for each of the heroines.
Environments and objects in game are also generally non-interactive and non-free-roaming, but some background animations have been added to the series, starting with You That Become A Memory ~Memories Off~, in order to enhance the visual experience.
Subsequent titles were tied together based on the ending of a specific route from the previous installment.
The first seven games in the main series are planned for release across two collections titled Memories Off Historia Vol.