Not much to say other than if you never heard of this manga, you need to read it now. It is a story that breaks all the normal tropes of your typical high school romances with well rounded, flawed characters that grow and learn as the story progresses. All the conflicts our main couple face are delt in a very real and original way with no (for the most part) unnecessary drama or forced situations.
This is a nearly flawless story that'll leave you wanting more after the series ends, even though it has a satisfying conclusion.
If you have a pulse, are breathing, and know how to read, I highly recommend Tonari no Kaibutsu-Kun.
~WiruSempai