Framed and sent to Kokuyoku Prison for embezzlement, Hina Saotome desperately wants to prove her innocence. However, just when she thought her situation couldn't get any worse, she realizes that she is the only woman in a prison populated by men. But she may have even more to fear from Aki Myoujin, a handsome and stern warden who is intent on punishing her for an unknown reason. Although the warden's treatment is unconventional, Hina's body soon begins to long for Aki's particular brand of discipline. But has this hypnotizing man, who has captivated her body, captured her heart as well? The story is set in a prison in the near future. It revolves around Hina Saotome, imprisoned despite her innocence, and the elegant yet sadistic guard Aki Myoujin. Hina's heart and body are at the mercy of Myoujin's "heartless yet sweet domination" from physical examinations to lovers' prison visits.