Beatrice Bibi Reden is a wealthy troublemaker at her high school, deeply fixated on the most popular boy, Peter. When she sees the quiet, timid Amy Lee talking to him, Bibi invites Amy to a sleepover with the intent to scare her off. Instead, Bibi finds herself unexpectedly enjoying their time together, and the two strike a deal: they will become friends on the condition that Amy helps Bibi win Peter’s heart. As they devise romantic schemes, Bibi’s obsessive attention gradually shifts from Peter to Amy, and what begins as a calculated friendship slowly turns into genuine romantic feelings.

The story is set in an American high school and follows both girls as they navigate their deeply troubled pasts. Bibi has exhibited violent and possessive tendencies since childhood, and her guardian fears she lacks basic human empathy. Amy, a Korean immigrant, carries the trauma of a mother who once tried to kill her, leaving her with severe self-worth and abandonment issues despite being raised by a loving aunt. Their relationship becomes a strange but healing balance: Bibi’s unapologetic possessiveness breaks through Amy’s emotional walls, while Amy’s gentle kindness fills the empty spaces in Bibi’s life. The narrative arc traces their growth from a manipulative pact through jealousy, confrontation, therapy, and moments of dark comedy, culminating in a genuine, supportive partnership. By the epilogue, the two have married and built a quiet domestic life together. Supporting characters—including Amy’s loyal friend Camilla, the oblivious Peter, and Bibi’s guardian Nicholas—add depth to the school setting and highlight the central couple’s unusual bond. The series balances a cutesy art style with psychological drama, exploring how love can exist even in the darkest places.