Before Cho was born, his parents moved to the west coast of United States from Japan. Cho was born soon after. He grew up, being taught his family's traditional culture, having trained his entire life in the ways of the ninja. He also grew up in the contemporary American culture. He completed his training at 16. In Cho's 10th grade year, a criminal came into the school while running from the police. The criminal was not in his right mind, and began shooting through the school. Cho lost seven friends that day; having held his best friend, since kindergarten, until she died.