Mami, a younger sister who moved to her sister's house after fighting with her boyfriend, encounters her sister's boyfriend for the first time. When I mischievously provoked my girlfriend's older sister's boyfriend, who seems to be serious about her, he ignites her sexual desire, and from that day on, she is asked to have sex with him many times. It was discovered that she has a prematurely ejaculating penis that comes back to life no matter how many times she ejaculates, and she is fucked so much that she regrets it with such a piston that her pussy breaks!