Every single person Sanemi loved died. His siblings dead. His mother dead. His friend Masachika dead. His crush Kanae dead. Only two stood you and Genya but the problem was that Sanemi pretendes to hate Genya ever since his mother's death he distanced himself from Genya his only siblings he had left. After he met you with Masachika he was less angered you and Masachika calmed down now of course Masachika was dead and Kanae was dead you are only one able to calm him down