When he was a 2nd year in junior high school and Tsubasa was in his 3rd year, his school team Nakahara had a friendly match with Nankatsu, which was a totally one-sided match. Frustrated by his teammates attitude, who were just happy to play and lose against such a famous opponent, going against the coach's directives, he took the ball from Izawa, then got past Kisugi, Taki, Ishizaki and Takasugi, but lost the ball against Tsubasa. Injured, the coach subbed him out for going against his directives. This bad experience almost led him to quit the soccer club and soccer altogether, but as if he knew what was in his heart, Tsubasa told him to not give up soccer if he liked it, and he remembered this afterwards when he was feeling desperate (World youth arc, chapter 1, pages 25 to 39). He was also touched by Tsubasa's speech when he won the International Jr. youth tournament in France, when mentionning Japan winning the World cup (World youth arc, chapter 1, pages 40-41). He went to see Tsubasa at the airport before he left for Brazil, and was surprised to see that Tsubasa remembered him, and by giving him three coins, 25 cents, 10 french Francs and 100 yens, Tsubasa made him understand the after the World cup in America and in France, he wanted to participate and win the World cup held in Japan (World youth arc, chapter 1, pages 42 to 48).
During his 3rd year of Junior high school, he became the captain of Nakahara, but never made it in the national tournament, still, he didn't give up and worked even harder (World youth arc, chapter 2, pages 24-25).

He decided to go to Italy after gratuating, and apparently even had an argument with his dad and his mom, but had support from his sister Yukiko (World youth arc, chapter 54, pages 48-49). So after graduating, at 15, he went to Italy, hoping that his uncle Shinnosuke would introduce him to some club. However, his uncle Shinnosuke suddenly died and he arrived when it was the funerals. Still his uncle talked about him and a woman allowed him to rent a place to stay (World youth arc, chapter 1, page 8). He

tried to join Inter and AC Milan, but without any recommandation, both teams rejected him (World youth arc, chapter 1, pages 4 to 8). Then he was tricked by a con artist, who, under the premise of introducing him to the coach of the Inter juniores team, asked him money for an admission fee to a selection, which, of course was never happening in the first place. He then tried to find a job to pay his rent but nobody wanted him because he was japanese: he ended up working with a shoe shining set that a man, arrested by the police, left behind. He also made a show, thanks to his great juggling skills, to attract more customers, and managed to solve his money problems this way (World youth arc, chapter 1, pages 9 to 23).
Training on his own, one day, dribbling all the way to Inter's training field, he'll help Calimero polishing spikes. To thank him, he'll invite him see the Milan derby: the Serie A match between Inter Milan and AC Milan. Calimero will realize that he has legs built for soccer and that he loves the sport, so much that he'll shed tears during the match. The next day, Calimero'll let him use the ground, and take him as an assistant to take care of the equipement. One of the Inter juniores player will get injured during training, and Calimero will introduce him so he has a chance to show his skills. Despite being not trusted by his own teammates, after stealing the ball from his own teammate, he'll make a good impression by dribbling past many players, and scoring a goal to Gino with an overhead (World youth arc, chapter 2, pages 2 to 33).
Him and Gino will become friends, by talking about Tsubasa whom Gino faced in the International Jr. youth tournament, but he was the only one, because, led by Matteo, holding a grudge against him since one of Matteo's teammate was expelled since his arrival, most of the players will give him a hard time, purposedly sending him bad passes, tackling or charging him violently, and not keeping up with his passes, even tearing up his bag and clothes in the locker room. Calimero will convince him that it's a good opportunity for his training, then, fired up by the news of Tsubasa becoming a pro at 17, will look like he'll give up and make the coach doubt him, but will in fact train even harder outside of the field to be able to keep up with everything bad his teammates are throwing at him, a training field that he nicknamed the "Shingo Special N°1" (World youth arc, chapter 3, pages 2 to 19). He will be given his last chance during a game where Inter will be led 0-1. Thanks to special weighted spikes given to him by Calimero, a weighted jersey and his special training, despite the mischief of his teammates who wants to take the opportunity of his last chance to make him expelled, he'll perform well and tie. Seeing this, and hearing Gino talk about his hard work, Matteo will eventually play to win and help him, and thanks to their cooperation they will win the match (World youth arc, chapter 4, pages 2 to 19).