Shinkurou Kurenai is a 16-year-old student during the day and a dispute mediator at night. Although he is kind-hearted and patient, his tragic past has driven him to train for years in order to survive. Now, despite his unassuming appearance, he is a skilled martial artist who also possesses a strange power. While working various jobs for his employer, Benika Juuzawa, one assignment leads Shinkurou to live with Murasaki Kuhouin as her bodyguard. Murasaki is the seven-year-old daughter of a plutocratic family who escaped her home under peculiar circumstances with Benika's help. Commoner life seems bizarre to her. However, by interacting with her neighbors, she becomes more accustomed to the daily routine, sheds her snobbish behavior, and gradually grows attached to Shinkurou. Although many details of the job remain unclear, Shinkurou still strives to protect the young lady. But to complicate matters further, he also lacks a crucial fact—what is the real threat against Murasaki?