On 12 March 2015, Miyamoto was crowned as Miss Universe Japan 2015 (Miss Japan 2015) at Hotel Chinzanso Tokyo in Bunkyō-ku, while Miss Oita and Miss Chiba were the runners-up.
Pada 12 Maret 2015, Miyamoto dimahkotai sebagai Miss Universe Japan 2015 (Miss Japan 2015) di Hotel Chinzanso Tokyo di Bunkyō, sementara Miss Oita dan Chiba dianugerahi sebagai runner-up pada acara tersebut.