 If you liked
Toaru Majutsu no Index
|
 ...then you might like
Bakemonogatari
|
Main character finds himself constantly in situations in which feels obligated to someone from supernatural danger, usually using supernatural means himself to do the saving. Most of the characters in need of saving are girls and so a defacto harem gradually builds around the protagonist, though in those cases the harem element thanskfully doesn't make the story go bad.