Grendel Jinx : A lazy, megalomaniacal kleptomaniac
Five years ago, she nearly suffered a fatal and self-inflicted accident during a school outing, saved only by the protagonist's fortuitous presence.
After rescuing her, the protagonist is promptly coerced into signing a "Friendship Agreement" form - a document designed to tie the protagonist to Grendel, both personally and financially, and then ultimately for the protagonist to join Grendel's organisation.
With the arrival of the last day of term, Grendel needs to hand in her remaining homework or face the prospect of repeating a year.
Drafting in the protagonist to solve her problem, Grendel is annoyed when her demands are swiftly rebuffed.
Initiating a devious plan to ensure her education can progress without interruption, Grendel's actions soon attract her mother's attention, who has her own nefarious plans for the protagonist.