Take-Two Interactive originally had a sequel in the works for Oni, titled, "Oni 2". The game was being developed by Angel Studios and was working on improving the combat system. However, due to time constraints and a lack of direction, the production was canned early on, leaving only an early techdemo.

There were many internal disputes about Konoko's appearance in the game between the Chicago and California divisions of Bungie, which was probably brought on by the presence of other female protagonists at the time such as Lara Croft.

Lead Engineer Brent Pease said in an interview that a majority of elements in the game Oni, such as having a female lead, hand-to-hand martial arts, and gunplay, were inspired by the anime film Ghost in the Shell.