To Aru Majutsu no Index Episode 04

Touma and Kaori starts to fight each other. However, Kaori's ability is far beyond than Touma expected. Touma who can't use his right hand gets hurt little by little, but he doesn't want to give up that easily. In the middle of battle, Touma asks Kaori why a strong person like her uses her power to hurt other people instead of protecting them. Kaori suddenly stops the battle and tells Touma the reason why she and Stiyl chase Index. From Kaori's explanation, it's revealed that Index has perfect memorization ability which allows her to remember everything with a single glance. Because of it, 85% of Index's brain capacity is allocated to 103,000 grimoires and only 15% is left to be used by her. If Index keeps memorizing something into her remaining 15%, she will die. In order to prevent it from happening, Kaori and Stiyl need to bring her to magic society to erase her memories every year. After Touma heard the truth, he gets confused, but he still doesn't want to hand Index over to them. Because Touma believes that Index's memories are important to her.







p.s. the story becomes more complex O_O