Behind a strong man [Ushiwaka /Oc]

Behind every strong man stands someone who supports him, comforts him, struggles with him and succeeds with him. Kageyama has such a person as his foundation and if anything would happen to her, he would shatter. [Ushiwaka/OC] This story revolves around Kageyama's older sister, a student at Shiratorizawa Academy and f...