Minazuki Sora

Sora is in the same grade as Kou. She is also Minazuki Makoto's elder sister and dotes on her, having once beaten up someone for making Makoto cry. She often jumps to conclusions without analysing the situation, but is at heart an honest and good-natured girl with compassion for the weak. She does not get along well with Kou initially, though she eventually develops feelings for him.

Spoiler

During the events of Gray Christmas, Sora headed to the Drexler Organisation's headquarters to perform a favour for Kirishima Rain, but was subsequently caught in and dissolved by the escaping Assembler nanovirus while in a call with Kou.