Yuu and Yuria started living with their new stepfather due to their mother's remarriage. Both were secretly working in the sex industry, but one day, their stepfather unwittingly booked them for a threesome course. 'How dare they do this while mom is around,' the two scoffed. Meanwhile, due to the economic downturn, Yuu got fired from her job at the sex club. Struggling with her income, Yuu decided to exploit her stepfather's interest in sex work, using her honed erotic techniques to demand money. Seeing the two having sex, Yuria also began to compete with her sister…
