A Wish and a Deal

One wish. Hiro made one wish. And then it came true. Tadashi is alive. However, he has no memory what happen after the fire accident. What happen to Tadashi? A strange boy knows what happen to Tadashi and his memory. Rated T. Pairings might show up depending on how story progress. OC will have a power from To Aru Majutsu no Index. I suck at summary.