Masako Ishida lives in Hokkaido and starts for the JR Hokkaidō Ski Team . She contested her first international FIS race in December 1997 in Otoineppu . Further appearances until 2000 were of a sporadic nature and only in low-class FIS and Continental Cup races. At the Junior World Championship in 2000 in Štrbské Pleso the best result was a 13th place over 15 kilometers. After the Junior World Championships, she ran for the first time on the podium in the Continental Cup in Hakuba and Sapporo . In January 2001 she won the first of these races in Hakuba. In 2001, Ishida also took part in the Winter Universiade in Zakopane and narrowly missed a medal in fourth place. In March the Japanese competed in her first cross-country world cup race in Oslo and was 54th. In 2003 she took part again in the Winter Universiade and achieved eighth place over 5 kilometers as the best result. After the Universiade, Ishida was nominated for a Nordic World Ski Championship for the first time . In Val di Fiemme she was 36th over 15 and 35th over 10 kilometers. With the season she ran to eleventh place. In November 2003 she won World Cup points for the first time in a race over 10 kilometers in Kuusamo when she was 29th. In December she was able to finish fifth with the season. Ishida ran her first World Championship in Oberstdorf in 2005 and was 42nd in the pursuit, 28th over 30 kilometers and 12th in the relay race. In 2006, the Japanese achieved a good new position in 14th place over 10 kilometers in Davos . After that they took part in the 2006 Olympic Winter Games of Turin in part and was 35th in the pursuit, 31, 10-kilometer and 12 in the relay competition. The next major event was the Nordic World Ski Championships 2007 in Sapporo, where Ishida came 26th in the pursuit and 13th over 30 kilometers. The Japanese made her best career achievements in the 2008/09 season . First she just missed a first top ten finish in eleventh place in a World Cup race in Valdidentro . Then she took part in the Nordic World Ski Championships 2009 in Liberec . There she was eighth in the 10-kilometer race, 14th in the pursuit and seventh in the relay. In the team sprint, she barely missed her first medal with Madoka Natsumi in fourth place. At the World Cup in Trondheim , she achieved her first podium finish with third place over 50 kilometers (mass start). In the overall ranking of the cross-country skiing world cup, she finished 33rd this season.
At the beginning of the 2009/10 season, she finished eighth twice in Rogla and Otepää . Placements outside of the points followed. At the 2010 Winter Olympics in Vancouver , she came 20th in the 15 km pursuit race, eighth place with the relay and fifth place in the 30 km mass start race. Silver won the 10 km freestyle and relay at the 2011 Asian Winter Games . She won gold over 5 km classic and in the 15 km mass start race. Her best results at the following Nordic World Ski Championships in 2011 in Oslo were eleventh place in the 15 km pursuit race and eighth place in the team sprint. In the 2011/12 season she reached several top ten placements in the World Cup. The Tour de Ski 2011/12 she finished in 12th place. At the Nordic World Ski Championships in 2013 in Val di Fiemme , she achieved tenth place in the skiathlon and the place in the 30 km mass start race. After a weak start at the Tour de Ski 2013/14 , she achieved tenth place in the overall standings thanks to good results in the last two stage races. Her best placement at the 2014 Winter Olympics in Sochi was tenth in the skiathlon.
On January 11, 2015, she took part in a race in the Ski Classics series for the first time and came second in the Jizera Mountains Run. A week later she was able to secure victory at the next race in the series, La Diagonela in Switzerland. In the following season she won third place at the Toblach-Cortina , the Birkebeinerrennet and the Årefjällsloppet and thus achieved fourth place in the overall ranking of the Ski Classics . In the 2016/17 season she came third at the Vasaloppet China and the Birkebeinerrennet and second at the Reistadløpet . In the 2017/18 season she took 22nd place in the Ruka Triple and 17th place in the World Cup finals in Falun . In addition, she was third in the Kaiser Maximilian run and first in the Reistadløpet over 50 km classic and thus achieved ninth place in the overall ranking of the ski classics. At the 2018 Winter Olympics in Pyeongchang , she ran in 18th place over 10 km freestyle, 14th place in skiathlon and tenth place in the 30 km mass start race.
In the 2018/19 season, Ishida finished 31st in the Lillehammer Triple and eighth in the 2018/19 Tour de Ski , making it 26th in the overall World Cup and 18th in the Distance World Cup. At the season highlight, the Nordic World Ski Championships 2019 in Seefeld in Tirol , she ran on 26th place over 10 km classic, 24th place in the 30 km mass start race and 14th place with the relay. In the following season she ran to 20th place in the Ruka Triple, to 23rd place in the ski tour and thus reached 41st place in the overall World Cup.
Ishida has run more than 200 World Cups so far, in about half of which she was able to win World Cup points. She won five races of the Continental Cup, as well as 16 races of the Far East Cup (as of the end of the 2019/20 season).