Natsuki is a nurse who is awkward when it comes to relationships. One day, as she's caring for an injured patient, Ryuji Kusakabe, a rugged and handsome CEO, she happens to see that he's extremely well-endowed. Following the shock of this sight, she can't stop thinking about him. After a period, the two of them just happen to bump into each other and begin a relationship. Natsuki still can't get used to being with a man, but she's in love with Ryuji. Ryuji basically prefers to be very sweet on the girls he falls for. As the two of them get hot and heavy, Ryuji's uncontrollably huge member seems to keep getting in the way...? Because he's so big, she's hesitant at first... but then, she keeps wanting more. What's happening with Natsuki's body...!?"