My Twin Sister Was Taken as the Miko and I Was Thrown Away but I'm Probably the Miko summary:
Lerunda has always been treated unfairly, constantly compared to her twin sister, whose personality is bright and beautiful. One day Lerunda was thrown away into the forest, abandoned by her parents when her sister was taken over to the Great Temple as a child… In disappointment, the strongest monster Griffon in the forest and a Sky Horse helped her lonely person…