Born in Nagoya, Ito started skating at age 5. Midori landed her first triple jump at age 8. She won her first national championship in 1985, having already participated in the World Championships one year earlier. She placed 5th at the 1988 Winter Olympics in Calgary, Canada. Later that same year, she perfected the triple Axel which she had been working on since her early teens and she became the first woman to land a triple axel in competition, when competing at a regional competition in the Aichi prefecture. She would repeat this feat at both the 1988 NHK international later that fall, and then the World Championships in 1989. Her win at the 1989 World Championships was the first world title in the sport for an Asian competitor. She received five 6.0s for technical merit. She did not ret