Hanyou no Yashahime: Sengoku Otogizoushi

Half-demon twins Towa and Setsuna grow up together in feudal Japan until a forest fire separates them and throws Towa through a time portal into the modern era. She is raised by the Higurashi family for 10 years before the passage finally opens again. Setsuna returns as a demon slayer, but to Towa's shock she remembers nothing about having a sister. Joined by Moroha, the daughter of Inuyasha and Kagome, the girls travel between eras searching for the cause of Setsuna's lost memories and the secrets surrounding their families. For Towa, reunion means more than finding Setsuna; she must rebuild a bond that only one of them remembers.