chang'e (touhou)
Chang'e is an enigmatic character. Little is known about her except that she lived on the Moon and was mistress of the moon rabbits before drinking the Hourai Elixir and becoming immortal, for which crime she was imprisoned for her now-eternal life. Today, the moon rabbits sing in unison when pounding mochi to atone for her sin of drinking the elixir.
It was unknown what happened to her until Legacy of Lunatic Kingdom, when it was revealed that Junko and Hecatia Lapislazuli had a grudge towards her and that they intended on invading the Lunar Capital to reach her whilst she is still in prison.
While not yet officially seen, some fans have created unofficial designs for her