Toa, a knight girl who has risen to the rank of captain of the Royal Knights. For some reason, she raises her hand to the royal family and is expelled from the Royal Knights. Toa is transferred to St. Dorothea's Burial Ground, a dangerous cemetery where only male prisoners are sent. Toa enters the funeral garden dressed as a man to protect herself, and meets a group of sinners called the "Knights of Sin."

A dark fantasy of a reverse-Harsh x dark fantasy with a male-dressed girl knight and sinners with strong personalities begins!