Mu Huiyue's younger sister who looks exactly like her twin. She appeared when Mu Huiyue was eight years old, brought back by a Beast Master who claimed Mu Huiyue's mother saved her in an S-class secret realm. Mu Yixia had already awakened as a Beast Master before Mu Huiyue. She was the person Mu Huiyue had arranged to meet in the park but did not show up.
