[2][3] However, he spent most of his high school years playing at JFA Academy Fukushima, which moved to Gotemba, Shizuoka following the 2011 Tōhoku earthquake and tsunami.
In 2014, he made his first appearance for JFA Academy Fukushima in the Prince Takamado Cup U-18 Football League aged 16, coming on as a late substitute.
[5] In 2016, Miyamoto helped JFA Academy Fukushima to the quarter-finals of the Japan Club Youth Cup, where he scored in their 3–2 defeat to Vissel Kobe U-18s.
[11] He made his debut for the team in March in a 2–1 league victory over Veertien Mie and scored his first goal in a 2–0 win over MIO Biwako Shiga.
Still mainly used as a central midfielder, towards the latter half of the season he began to play in the right-back position and he helped secure Iwaki's safety in the J2 League.