At the 2017–18 Japan Figure Skating Championships, Sakamoto won the short program. In the free skate, she placed fourth and won the silver medal, her first senior national medal. Following the competition, the Japan Skating Federation named Sakamoto in Japan's team to the 2018 Winter Olympics, alongside Satoko Miyahara. Sakamoto was named in Japan's team to the 2018 Four Continents Championships with Miyahara and training-mate Mai Mihara. She was also selected as the first alternate for the 2018 World Championships, behind Miyahara and Wakaba Higuchi.