Wataru Miyauchi is a right-handed batter and wicketkeeper who has become an established figure in Japan's senior cricket setup. A product of Japan's domestic pathway, he developed his game through school cricket and went on to represent the West Kanto Hurricanes and Wyverns Cricket Club.

Miyauchi made his T20 International (T20I) debut in 2023 against the Philippines during the ICC Men's T20 World Cup East Asia-Pacific Qualifier in Port Moresby. Later that year, his swift rise in the national side earned him selection in Japan's squad for the delayed 2022 Asian Games in Hangzhou, held in autumn 2023.

He continued to anchor the middle order and provide consistency behind the stumps, reaching a key personal milestone in May 2024. During the ICC Men's T20 World Cup Sub Regional EAP Qualifier, Miyauchi struck his maiden T20I half-century, a career-best 72 off 54 balls against Mongolia to earn the Player of the Match award.

Now an experienced core member of the national setup, Miyauchi has also been named in Japan's squad for the 2026 Asian Games in Aichi-Nagoya, where he will feature in his second consecutive continental multi-sport event.