HEZ-821 Jun Mizukawa, an innocent nurse who has been pushed to the limits of both her physical and mental strength after 10 consecutive night shifts, is consumed by sexual desire and turns into a sex zombie.

My older sister is my pride and joy. She had excellent grades in school. She's good at her job, pure and innocent, and the ideal woman that even other women admire. One day, she accepts an unreasonable shift and before she knows it, she's worked 10 night shifts in a row! She's exhausted, both mentally and physically, and her reason is completely consumed by her sexual desire... To reward herself for her hard work, she drinks alcohol, which triggers her sexual desire and completely consumes her reason...