When Sonoda visited the Gold Coast, Australia with his family at age 13, he decided to study in the Gold Coast because the town has many golf courses.
He spent two years in a junior high school there to pursue his golf game further. He won the Japan National Junior Golf Championship.
He decided to return to Japan to enter Suginami-Gakuin High School. He was a high school teammate of Ryo Ishikawa. Ishikawa calls him “King” as he swept all the junior tournaments. They first met in elementary school. In his sophomore year at the Meiji University, he qualified for Japan Golf Tour.
Sonoda began playing on the Japan Golf Tour in 2010 and won the 2010 Gateway to the Open Mizuno Open Yomiuri Classic. This victory earned him an exemption into the 2010 Open Championship.
