Though it was a little over the top, I can totally understand Kurokawa here, when you're told "you're not good enough" a million times by literally everyone around you growing up, you end up believing it, causing you to end up with bad self esteem, which would lead the thoughts like "I'm not worthy enough to stand by their side" or "I'm not that special, so why me?" even if they do love the other person.
for me Fujishiro has to be the one to set kurokawa straight, I don't want this to develop into the kind of situation where they stop talking for and extended period of time and kill all communication. that would lead to a situation where the friends have to step in and try and fix it and I don't feel like that's proper with how kurokawa is.
Agreed, though sweet, it'd definitely feel a little hollow for the friends to have to step in, these kinds of problems are really only solved if the two are willing to confront each other and actually communicate.