Yuichi and Mikaela were lovers in the past, until a great war happened between two sides. It was an all out war against the impurities and the purificators. One by one , their powers were getting stronger and stronger to the point where they were neck to neck. Nobody won the great war. Lives were lost at a tragic state. It was the same for the lovers. Yuu promised her eternity. But fate was cruel to the both of them. Now as they begin anew with their new lives, their past was erased along with their memories. Only remained was a hollow spots in their hearts with unknown promises yet to be fullfilled.