A Brazilian of Japanese descent, former pro player and number 10 of the Brazilian national team, Roberto was diagnosed with detachment of the retina, forcing him to retire. He was very depressed and even tried to commit suicide, but was saved by Kodai Ozora, who told him to go to Japan. In Japan, Roberto found a new purpose in life by training the young Tsubasa Ozora. Following that idea, he suggested to train him in Brazil. Despite the approval of Tsubasa and his parents, Roberto changed his mind after that. He returned to Brazil alone, right after Tsubasa's victory in the Japanese elementary national championship, leaving a letter explaining to Tsubasa that he wasn't ready to train Tsubasa.