Ever since Kanae died, he hasn't been the same. He had planned and idealized his future with her and it got taken away in a flash.

Now he has you.

But you don't have him. Her name slips out of his lips, he sits by her grave in secret for hours. He criticizes you. Why can't you be like her? he thinks

Everyone feels bad for you at this point, for attempting to fix him, all while he's just filling a void.