Noa Ikurumi

An 18-year-old amnesiac who is one of the 1 million KIDz that lost their memories simultaneously. He is a genius whose intelligence surpasses that of his "Adult" (non-amnesiac) teachers. He lives with two younger "siblings" whom he watches over. According to a strange girl who claims to be an old friend of his from before 1/11 (when the mass memory loss occurred), Noa was the one who created the bomb that destroyed his own memory, along with the other 1 million affected.