彼女・みずきの家にやってきたとおるは、みずきの妹「さりな」と出会う。ダウナー系でクールなさりなだが、みずきには見えない所で淫語＆エロ仕掛けで誘惑！？ムラっとして勃起してしまうと、みずきに隠れて手コキやフェラで射精させられてしまう！さりなの誘惑はどんどんエスカレートしてセックスまでしてしまう！容赦ない誘惑に理性はぶっ壊れ…中出しは止まらない…
When Toru arrives at his girlfriend Mizuki's house, he meets Mizuki's younger sister, Sarina. Sarina is a cool, downbeat type, but when Mizuki isn't looking, she seduces him with dirty talk and erotic tricks! When he gets turned on and gets an erection, she makes him ejaculate with handjobs and blowjobs while Mizuki is away! Sarina's seduction escalates more and more until they have sex! His reason is shattered by her relentless seduction… and he can't stop cumming inside her…

– JavGG.net