Shintaro is a young man who is a shut-in with an IQ of 168. Although he scored top-rank scores on the national mock exams in middle and high school, he dropped out in his first year due to the suicide of his best friend, Ayano. Ever since, he has been living a life of exasperation with Ene, a mysterious program that has infected his PC. He is Momo’s older brother.
His special ability is his "Retaining Eyes", given by Marry after he promises to never forget the tragedy that happened to Ayano. This special ability allows him to remember everything he sees.