Not much is known about Tenma's childhood, however when he was growing up in Japan, he was constantly getting picked on and had a habit of wetting his pants. This earned him the nickname of "Sissy Pants Tenma". As well, Kenzo's father and brother were also doctors, possibly leading to his decision to also pursue a career in medicine. However as Tenma was not a person who was close to his family, he had chosen to attend a University in Germany to study medicine. As such his ties to his family have since grown weaker as he had not been back in Japan since he left.