Tonari no Kaibutsu-kun is your Bonnie and Clyde romance between a violent sociopath of a guy and an emotionless study-obsessed girl. Neither do well with the conventional norms of society but somehow manage to find each other and eke their way towards a non typical relationship.
While it's similar to the recommended titles below like Bokura ga Ita, Kimi ni Todoke, etc, it's a lot quirkier and less emotionally driven. You don't feel overwhelmed with characters overflowing miasma of emotional turmoil as is typical in this genre. It's definitely more lightweight and humorous… maybe along the lines of Yamato Nadeshiko Shichi Henge.
I'm quite a fan of the studious Shizuku who is a role model for young teens to not let romance detract you from your life long goals! Very level-headed that one. And you get to see her struggle and figure out just exactly what her priorities in life are and how to balance it all.
Her counterpart Haru has his share of struggles. He's deep down a nice guy that wants to do well but has never had the emotional support or encouragement to bother trying. Instead the rage and anger that stems from his troubled upbringings often bubbles to the surface and obliterates the nicer side of him.
There is a surprising level of emotional maturity between the two or perhaps its that they both lack the social acuity necessary for subtlety so their interaction is quite frank and direct. It's quite refreshing to watch! You're not waiting around for them to confess but instead the anime is about their struggle to pursue a relationship despite clashing personalities and internal struggles.
At the end of the 13 episodes, their relationship is still at its infancy and there is much development necessary. Hopefully there will be a season two!
Must say, I'm secretly routing for Kenji. I'm a little tired of the bad-boy type that seems to prevail in these shoujo-romances. I mean seriously, Haru's hit Shizuku numerous times with nary an apology, is not above stalking her, trying to control her and wouldn't hesitate to push people off buildings in the name of jealousy.
This does not a good boyfriend make!
If I was her mother I'd say "Go for that hot blond fellow, that's attending cram school just spend time with you, treats you well... and is filthy rich." Some parenting for y'all!