Black cat Tsubaki becomes a black swan――and the young lady becomes a white swan... A story of a witch facing this extreme situation.

The black cat Tsubaki is the familiar of the witch Condessa (a beautiful woman in her 20s). On a day when Condessa is away, a high school witch named Chileena visits Tsubaki, who is housesitting at home. Chileena asks Tsubaki for help, saying "I want to convey my passionate feelings to Condessa, my big sister..." but... This is a side story to "The Black Cat Tsubaki and the Witch Condessa." You may also read it as a standalone work.