Ichiroshi Ma Hiro, a second-year office lady whose mother remarried and now lives with her stepfather and stepbrother. Bored with many remote work situations due to the pandemic, she accidentally discovers that her stepbrother has a large penis and becomes aroused. She seduces her stepbrother during his online classes, engaging in relentless daytime sex. Eventually, they run out of condoms and end up having unprotected sex (creampie).
