 If you liked
Toaru Majutsu no Index
|
 ...then you might like
Machine-Doll wa Kizutsukanai
|
The biggest similarity would definitely be the main characters. They're both hospital-bound idiots who rush into things without looking at the consequences. Both go out of their way for their female companions. They attend a school where some sort of supernatural art is taught is taught. There's a female with the protagonists at all times (Toaru – Index/Machine-doll – Yaya). And there is a certain aspect of badassery with both characters as well.