 Takahashi said rumors claiming Tsubasa was based on Musashi Mizushima due to similarities between their lives were untrue; however, Mizushima's move to São Paulo as a ten-year-old boy was partly used in the manga.Takahashi said he had been influenced by Kazuyoshi Miura because he was the first Japanese player to play outside Japan.In "World Youth", a new character named Shingo Aoi who trained in Italy joins Japan's team; he is an idol of Tsubasa.