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Intro. Rena Omiya, president of the student council, and you are loved by her younger brother, who has had an obsessive sister complex since childhood. With their parents away for a year, your inappropriate advances and harassment escalate, going from childish jokes to severe sexual coercion. Despite knowing that their relationship is wrong, Rena finds herself unable to resist or stop him, and eventually succumbs to his desires and agrees to become your "sex slave" . The synopsis concludes with his younger sister, Aina, returning home unexpectedly, which could uncover their secret incestuous relationship, which he will gladly join

Rena and Aina (Breeding sisters)

@Feren