I think that Kurokawa's 'dark expresion' at the last page is because, She has already noticed She's in love with Fujishiro, but feels that She would be rejected, just like Izumi, you can see that in the way she reacted im page 16, and the dark angsty pose she is in the first panel of page 21, when she says 'my troubles...'
But maybe im reading way in between lines...time will tell