deletes memory erasure

However, the alchemist casually said, “Don’t worry, I won’t kill him.”
He pulled out the needle from his neck, and said, “Young man, as for what happened
here—”
(Damn it, what kind of a sick joke is this! How can I back away now!)
The alchemist seemed to have seen through Kamijou’s heart and smiled.
He then said, “Forget about everything that happened here.”
***
Kamijou thought about Misawa Cram School that he never went to before, and muttered,
“Never mind. If I can’t remember, it’s probably not important.”
After making that conclusion, he continued to move forward.
Right now, the most important thing was how to calm down Index, who was angry that
she had nothing to eat. Seemed like he could only calm her down with a black honey
pudding that cost seven hundred yen. That unexpected cost really bothered Kamijou.
(I really shouldn’t have bought the 3,600 yen reference book.)
Kamijou sighed and scratched his head with his hand.
His right hand that could negate any supernatural powers, even a miracle of God.
With the sound of his skull breaking, the day’s memories rushed into Kamijou’s brain.
“...!”

- Toaru Majutsu no Index Volume 2, Chapter 3 Part 3