[Klashikari]

Well, it is nothing really fancy:

Spoiler for Kazuha's route:

Over time, Kazuha notice that she is spending less and less time with Akira, and out of guilt, wish to break up with Haru so she can focus back on Akira.

Suffice to say, Haru managed to prevent it from happening.

That being said, I can't consider it as a good idea, since it will definitely drain anyone's sympathy towards Haru down to the gutter.