Takeshi and Yui are about to move out together, but since they haven't found a home yet, Yui's mother suggests that they go to Yui's house temporarily. There, Takeshi first meets Yui's quiet sister Rei. Rei is extremely beautiful, but seems to be an extremely straightforward person. However, Rei often doesn't wear a bra when she's at home, making her big soft breasts sway every time she moves! Every time he saw this scene, Takeshi's cock immediately got an erection. One day, Takeshi went to the bathroom while Rei was removing her makeup. Watching Rei's tits hidden through the thin nightgown make Takeshi's cock erect again. At this moment, the power went out, and Rei unconsciously approached Takeshi in panic and sat down. When the power was restored, as soon as she turned her face, Takeshi's still-erect cock was pointed directly at her face. Seeing that he was discovered, Takeshi quickly apologized to Rei, but he didn't expect that Rei was not only not angry, but also took the initiative to suck his cock for him...