Born on August 24, 1996 in Kanagawa prefecture. Began gymnastics at 3 years of age, joining his parent’s gymnastics club in 3rd grade to fully commit to the sport.
Chosen for the Japan national team at the age of 16 for the Gymnastics Asian Championships in 2012, won gold in the men’s individual floor exercise. In 2013, won the men’s individual floor exercises at the All-Japan Gymnastics Competition Championship and was chosen as a member of the national team for the 2013 World Artistic Gymnastics Championships.
Enrolled at Nippon Sport Science University in 2015. Played a large role in the national team’s first win in 37 years at the World Artistic Gymnastics Championships, while also earning a gold in the men’s individual floor exercise. Introduced a new technique at the 2015 Toyoda International Gymnastics Competition, a backward triple-twisting double layout, later named the “Shirai III”.
Participated at his first Olympic games in 2016 at the Rio de Janeiro Olympics and performed in the vault and floor exercise in the all-around team finals, helping the national team win a gold medal. He successfully completed the Shirai II, a round-off, back-handspring into a 3.5-twisting layout with a 6.0 difficulty, capturing the bronze medal in the individual vault event. It was the first medal for Japan in 32 years in the event, and these accomplishments led to him being awarded the Purple Ribbon later that year.
In 2017, won his 5th gold medal in the individual floor exercise at the All-Japan Gymnastics Competition Championship, a first ever feat in the history of the tournament.