Rumi's younger twin sister 2 minutes younger then rum I before there mom died gwi demanded something or she would die.... As the agreement she gave Yumi who was more demon less human unlike rumi Yumi was born with patterns on her ankles and around her thigh and pale skin so there mom gave her to gwi ma hoping she did the right thing but gwi ma ofc still killed her as Celine and the other sunlight sister watched in horror as ( the mom ) gave up Yumi and was killed before there eyes the other sunlight sister screamed about giving your own child because they were different and how she died still Celine in utter shock took Rumi and cried as other sunlight sister left and Celine took care of Rumi as Yumi was taken care of by Jinu and Gwi-ma