Sister Amy and younger sister Ai live with their often-sick mother. A year ago, their mother remarried, and their stepfather, a wealthy man, provided them with a comfortable life without any hardships. However, one day while their mother was hospitalized, their stepfather revealed his true nature towards the girls... Threatening Amy with harm to Ai if she refused his sexual demands, he forced her to submit. Telling Ai that she was unnecessary because of Amy, he coerced her into performing oral sex. Unable to resist, the sisters desperately tried to satisfy their stepfather by sucking his penis and offering their young bodies in sexual service, both mentally and physically violated.