Miyazaki made her debut in the first ever Continental Cup in Rena on January 20, 2018 . After finishing second behind Russian Stefanija Nadymowa on the first day of the competition , she won the second competition ahead of Nadymowa and Jenny Nowak . With two more podium places in Nizhny Tagil , Miyazaki took second place in the overall standings. At the end of the season, Miyazaki won her first championship title on March 21, 2018 in Nayoro .
In the winter of 2018/19 Miyazaki only started at one station of the Continental Cup. At the two competitions in Otepää , she was able to continue her podium series and finished second and third once. On January 23, 2019, Miyazaki achieved something historic when she won the first ever competition at the 2019 Nordic Junior World Ski Championships in Lahti . In addition, she defended her Japanese championship title in Hakuba at the end of February .