Kuromi
My Melody’s rival has a record, and it begins the way the series does: in a cell.

The subject
Kuromi debuted in 2005 as the antagonist of the "Onegai My Melody" anime: a white rabbit in a black jester’s hood with a pink skull, and My Melody’s self-declared rival. Sanrio credits her design to Yuko Yamaguchi, a credit now disputed in court.
She is accompanied by Baku, a purple tapir, who carries out and absorbs most of the consequences.
The record
Imprisonment and escape
The series opens with Kuromi and Baku held in a dungeon in Mari Land. They break out and flee to the human world. Canon does not state the original offense.
Theft of the Melody Key
They take the Melody Key on the way out. In the human world Kuromi learns it grants wishes through dark power.
The Black Notes
Kuromi grants people’s wishes as nightmares. A nightmare the victim enjoys produces a Black Note, which Baku eats and stores. The plan is to gather one hundred and revive the Spirit of the Dark Power, which would consume the dreams of the human world.
My Melody
My Melody is sent with the Melody Takt to gather one hundred Pink Notes for Dream Power. The two run directly against each other.
She keeps a diary, the Kuromi Note, said to log every slight My Melody has ever dealt her. Despite the record, she is today one of Sanrio’s most popular characters.
The only real-world litigation touching Kuromi is the dispute over who designed her, which is this archive’s featured case. Studio Comet v. Sanrio