Aoki started internationally for the first time at the Winter Asian Games 1990 in Sapporo . There she won over 10 km classic, over 15 km freestyle and the gold medal with the relay. Her best placement at the 1991 Nordic World Ski Championships in Val di Fiemme was 13th place over 15 km classic and 19th place in the pursuit and 12th place in the relay at the 1992 Winter Olympics in Albertville . The following year she ran at the Nordic World Ski Championships in Falun on the 41st place over 5 km classic, on the 40th place over 30 km freestyle, on the 22nd place in the pursuit and on the 20th place over 15 km classic. At the 1994 Winter Olympics in Lillehammer she came in 26th place over 5 km classic and 30 km classic, on 16th place in the pursuit and on 11th place over 15 km freestyle. In the 1994/95 season she reached her first top ten places in the World Cup with two ninth places and at the end of the season the 34th place in the overall World Cup. At the season highlight, the Nordic World Ski Championships in 1995 in Thunder Bay , she achieved 44th place over 5 km classic and 41st place in the subsequent pursuit.
In the following season, Aoki made it into the points 12 times and thus achieved 22nd place in the overall World Cup. She achieved her best overall results in the World Cup in the 1996/97 season with 19th place in the overall World Cup and seventh place in the Sprint World Cup. She came in fifth three times and thus achieved her best individual result in the World Cup. Her best results at the Nordic World Ski Championships in 1997 in Trondheim were 26th place over 5 km classic and 15th place with the relay. At the 1998 Winter Olympics in Nagano she ran on the 37th place over 15 km classic, on the 31st place over 5 km classic and on the 29th place in the pursuit. In addition, she won tenth place in the season together with Tomomi Ōtaka , Sumiko Yokoyama and Kumiko Yokoyama . In the 1998/99 season she won the bronze medal over 10 km freestyle and the silver medal with the relay at the 1999 Asian Winter Games in Gangwon and took 47th place over 30 km classic, 41st place at the 1999 Nordic World Ski Championships in Ramsau am Dachstein 3rd place in the pursuit and 39th place over 5 km classic. She completed her last international competitions at the Nordic World Ski Championships in 2001 in Lahti . There she finished 52nd place over 10 km classic, 46th place in the skiathlon and 13th place with the relay.
Aoki was seven times Japanese champion over 15 km (1989, 1990, 1992–1995, 1997), six times over 10 km freestyle (1989, 1992-1996), five times over 5 km classic (1993-1997), three times over 30 km (1994 , 1995, 1997) and once each over 5 km (1988) and 10 km classic (1992). She also took three wins in the Continental Cup .
Participation in World Championships and Olympic Winter Games
winter Olympics
1992 Albertville : 12th place relay, 19th place 10 km pursuit, 30th place 5 km classic, 37th place 15 km classic, 44th place 30 km freestyle
1994 Lillehammer : 11th place 15 km freestyle, 16th place 10 km pursuit, 26th place 30 km classic, 26th place 5 km classic
1998 Nagano : 10th place relay, 29th place 10 km pursuit, 31st place 5 km classic, 37th place 15 km classic
Nordic World Ski Championships
1991 Val di Fiemme : 13th place 15 km classic, 16th place 10 km freestyle, 19th place 5 km classic, 22nd place 30 km freestyle
1993 Falun : 20th place 15 km classic, 22nd place 10 km pursuit, 40th place 30 km freestyle, 41st place 5 km classic
1995 Thunder Bay : 41st place 10 km pursuit, 44th place 5 km classic
1997 Trondheim : 15th place relay, 26th place 5 km classic, 28th place 15 km freestyle, 29th place 30 km classic, 30th place 10 km pursuit
1999 Ramsau am Dachstein : 39th place 5 km classic, 41st place 10 km pursuit, 47th place 30 km classic
2001 Lahti : 13th place relay, 46th place 10 km skiathlon, 52nd place 10 km classic
Japan
