In order to find a way to return to the original world, Anna, a transmigrator, enters as a maid of the Loengrin Estate, which has the ugly nickname 'Swan Tomb.' Marquis Rothbart encounters Anna by chance and recognizes as his missing wife when he was under the influence of an aphrodisiac. He gives her an unexpected proposal. "Be my wife on her behalf." In the meantime, Anna knows that in order to return to the original world, she must have a child with a person from this world. While contemplating, Svanhild, Rothbart's son, also hangs around her and begs. "I want you to be my mom, Anna." A relationship with a fixed end, with conditions that cannot be refused. Anna, who wants to return to her original world, accepts Rothbart's suggestion... . . "Master, please, ah, ah!" "Not master, but Roth." Rothbart whispers, kissing the tip of Anna's little chin. "I told you to call me Roth, my Ianna."