Sora isn't being "insufferable"- it's just that she's been confined to a hospital most of her life, is still physically weak
(heh doesn't affect her in be*), can't do much for herself at series start so depends on Haru, is socially awkward due to her lack of interaction with anyone except him and basically views him as the only person who ever really stood beside her in her entire life. Then she sees someone raep him, and now it seems that that very same person is going to take away the only one left who loves and cares for her. I think she's allowed to be a bit difficult in the circumstances
btw it's Nao
