This is one of the best manga i have ever read. Why you ask? It's simple:
First of all, i really love how the heroine acts. She is not the type that just stands in the way like an obstacle, she always wants to help, tries to be brave even when she is scared, she tries to do her best all the time. But the most important think is that she is not clingy.
Secondly, i like how every character has it's role. The story isn't rushed, their feelings evolve not too fast but not slow either. Their relationship is too cute and pure, it is beautiful to see how they care for each other. I hope you give this manga a chance, I promise you won't be disappointed. :)