After Mystery Mint's older sister, Sonata Dusk, comes to CHS for a project at her own school, the sisters get into a misunderstanding when barely anybody knows that Mystery has a sister.
Using HUMAN WORLD SONATA.
UPDATE NOTE: For anyone reading this, note Sonata will be entirely out of character, as this was written in May, when only her name and design had been announced.
UPDATE NOTE 2: I am currently in the process of revising this.