Nagahara attended Aomori Yamada High School, and was part of the Japanese national junior team that won the bronze medals at the 2013, 2014 Asian and 2014 World Junior Championships.

[4] Nagahara was awarded as the 2018 Most Improved Player of the Year by the BWF together with her partner Mayu Matsumoto.

In March, Nagahara and her partner Mayu Matsumoto won their first World Tour Super 1000 title in the All England Open defeating their compatriots, the defending champion, and current world number 1, Yuki Fukushima and Sayaka Hirota in the final.

[6] She competed at the 2020 Summer Olympics partnering Matsumoto as 3rd seeds, and her pace was stopped by Kim So-yeong and Kong Hee-yong of South Korea in the quarter-finals.

[7] Women's doubles Women's doubles The BWF World Tour, which was announced on 19 March 2017 and implemented in 2018,[9] is a series of elite badminton tournaments sanctioned by the Badminton World Federation (BWF).