If by Haru you mean Takumi Hira, well, it isn't like I don't agree, at least in part. His part in the whole thing was a bit sad/tragic. However, as you yourself said, it doesn't work unless it goes both ways, and it isn't like Akane doesn't like Kotarou and him her. In fact, quite the opposite! I think it better that they get together than Akane and Takumi get together and then Akane spend all her time wondering what she's missed, and/or Takumi spending time hating himself for being selfish. (Or worse, Akane hating him for not!) And at the core, if he really loved her that much then he should have said something a long time ago. Who knows, he might even have avoided the whole problem! Even - especially! - if he does love her now then really, what choice does he have except to let her go? No, it really has to be Akane and Kotarou.
Anyway, in my mind there's a second season or OVA somewhere where Chinatsu and Takumi get together so it all works out for the best after all.