He is a 14-year-old boy genius who graduated from the Stockholm Royal University of Science at the age of 13. His abilities are considered elite, even within DATS. He bases his operations on data and theoretical principles, and as such his personality clashes with Marcus's. His mother is Japanese and his father is a prominent Austrian aristocrat named Franz Norstein. Franz and Thomas' mother met while she was an exchange student in Austria, and Thomas lived with his mother in Japan until she died. He was taken back to Austria. He also has a younger half sister, Relena, who suffers from a strange disease. It is never shown who Relena's mother is, but she died of complications during childbirth. While Thomas does not particularly care for his cold father (at least not until after the events of episode 42), he does love his sister very much and does whatever he can to protect her.