In Touhou 12: Undefined Fantastic Object, which of these was not a playable character?

The reason why Izayoi Sakuya was not a playable character in Touhou 12: Undefined Fantastic Object is because she was not part of the roster for that particular game. Instead, players were able to control Reimu Hakurei, Marisa Kirisame, and Sanae Kochiya. Izayoi Sakuya's absence as a playable character may be due to the game's focus on different characters and storylines, or the developers may have chosen to introduce new playable characters for variety and fresh gameplay experiences.