Yuusuke Yamamoto grapples with a deep-seated fear of women, stemming from a traumatic childhood incident involving the twins next door. When his gynecologist father tasks him with overcoming this fear to take over the family business, Yuusuke reluctantly agrees to host the sisters, Rika and Yuka Nakamura. As tensions rise in their cramped living arrangement, Yuusuke is faced with a difficult decision: choosing which sister can stay. Both Rika's quiet charm and Yuka's bold advances vie for Yuusuke's attention, leading to a complex and intimate struggle for his affection.