Insecure, socially-awkward and with a habit of making sudden and profuse apologies, Asumi Torii is a strange girl who often fails to click with her peers... she also has an arrow stuck in her head. For new transfer student Ryouji Yamada, however, Asumi is the most interesting girl he's met. Simultaneously fascinating and unsettling though she may be, he dedicates himself to getting to know her and finding out what makes her tick. However her bizarre outlook on life - combined with the razor sharp arrow protruding from her head - makes it a painful learning experience for Ryouji.
The thing that connects those two series is the fact that one of the main characters has an arrow stuck in his\hers head. The theme seems to be rare enough to warrant a recommendation, but if that's not enough, I can add that female leads in both series are quite quirky.