"No matter what happens, I'll protect you." Teru, who lost her only remaining relative, her older brother, is cheered on by a mail from an enigmatic person, DAISY, who she can contact via the cellphone her brother gave her. One day, through an unexpected incident, Teru ends up working as a servant for the delinquent school janitor, Kurosaki. But this scoundrel, Kurosaki is really...!?