My father remarried and I live with my new mother and step-sister. I just started working and my step-sister Suzu is a female college student. We're close in age so we've had a slightly distant relationship until one day my parents go on honeymoon and we're left alone. What's more, a typhoon causes a power outage and Suzu hugs me in the pitch black. The distance between me, who is unsociable and strict, and the sociable and spoiled Suzu has become closer... I'm at the mercy of my sister who clings to me and pampers me with her huge breasts, and before I know it, our positions have been reversed! I'm drowning in her sweet tongue kiss hold!