A boy called Touma Kamijou, whose right hand has the ability to nullify all abnormal powers, wakes one morning to find a girl called Index draped over the railing of his balcony. She is the Index Librorum Prohibitorum, retaining 103,000 forbidden books of magic in her eidetic memory, and she is being chased by two sorcerers who desire those books. Or so it appears.
Not bad, but it has the light novel style quite strongly.