S to M no Sekai

Sekai Maihime survives a deadly train accident and is transported to 17th-century France, where she gains powers linked to a doll named 'S.' A guardian named Sovieul, who is responsible for her time displacement, assists and restricts her, offering minimal explanation for her situation. Sekai encounters Machiavello, who resembles her childhood friend and love interest, Midou. Machiavello seeks the powers shared by Sekai and 'S' to access the power of the Devil R. Sekai's main goal is to locate Midou and return to her original time, but her efforts are complicated by her conflicting desires with 'S' and Machiavello's pursuit of her body. To find Midou, she must work with 'S' and Sovieul while evading Machiavello.