In 2014, Nonaka transitioned towards competition bouldering, winning her first World Cup medal with a second-place finish at the Boulder World Cup in Laval and eventually finishing the World Cup season in fifth place in the overall ranking for bouldering.[1]
Nonaka continued to move up the overall rankings for bouldering in the following World Cup seasons, finishing in third place in 2015 and second place in 2016. She won her first World Cup gold medal at the Boulder World Cup in Navi Mumbai in 2016.[2]
In 2018, Nonaka won the overall title in the Boulder World Cup by earning a place on the podium at every World Cup that season, winning one gold medal and six silver medals.[3]
In preparation to compete in the combined event at the 2020 Summer Olympics (postponed to 2021), Nonaka competed at bouldering, lead climbing, and speed climbing events during the 2021 IFSC Climbing World Cup season, making finals across all disciplines and winning a bronze medal at the Speed World Cup in Salt Lake City.[9] At the Olympics, Nonaka won a silver medal in the combined event.[10]
Nonaka followed up her Olympic medal with two straight second-place finishes in the overall rankings of the Boulder World Cup in 2022 and 2023.
In 2024, Nonaka placed second in the rankings of the combined bouldering and lead climbing event at the Olympic Qualifier Series, securing a spot for the combined event at the 2024 Summer Olympics in Paris.[11] At the Olympics, she finished in ninth place in the semifinals of the combined event and did not move on to finals.[12]