In Episode 6 of "Tsundero," the protagonist, Yuuyo, experiences a significant change in his family dynamics when his father marries their neighbor, introducing two new stepsisters into his life: Hayaka, a nurse at his school, and Haruka, the gym teacher. An unexpected incident brings Yuuyo closer to his stepsisters, leading to intimate encounters that explore themes of familial relationships and desire. The episode delves into the complexities of these new bonds, highlighting the challenges and emotions that arise from their unconventional situation.