I usually ship the best friend but I can't in this case. It's sad and Izumi's misdirections are understandable but I've watched the 2 leads go from strangers to friends to slowly approaching something like romantic love. Fujishiro far more than Kurokawa at this point. In fact, It seems more like Kurokawa is only in the crush stage. It's probably too soon for Fujishiro to confess to Kurokawa, once she admits what Izumi already knows.
i can't really hate izumi since i've been there before with that exact thought, she's my best friend, and i'm satisfied with her just by my side with nothing changing