The black cat Tsubaki is surprised to see the moving emerald.

The black cat Tsubaki is the familiar of the witch Condessa (a beautiful woman in her twenties). On a rainy day during the rainy season, a high school witch named Chileena visits Condessa's house. Chileena, who adores Condessa, confidently shows off a present saying, "It's an emerald as beautiful as Condessa's big sister's green eyes!" Then, the emerald begins to move...... This is a side story of "The Black Cat Tsubaki and the Witch Condessa." You can read it as a standalone story without any problems. It is also posted on "Novel Up +" as well.