A father’s remarriage. For the protagonist, this means an unexpected stepsister is thrust into his life. His shock is palpable when he discovers it that she is that girl from his class, the one famous for her prodigious bust. She is the secret infatuation of virtually every male student, an unofficial campus idol who dominates their most private fantasies.
However, her understanding of family obligation is uniquely jarring. She is governed by the unwavering conviction that a sister’s sacred duty involves personally attending to her brother’s accumulated “frustrations.” Consequently, the protagonist finds himself in a dizzying paradox, perpetually pursued by the very girl he struggles to view as mere family. All the while, she remains blissfully, and utterly, convinced that her advances are simply the acts of a devoted sister.