Ayako Mukai went to school in Noheji, Aomori Prefecture, but now lives and trains in Sapporo . The soldier began biathlon in 2003. Before that she was active in Ekiden (long-distance relay race) and took part in the 2000 Ekiden competition in Aomori Prefecture. As is customary in Japan, as a biathlete, she initially belonged to the "winter combat training unit" of the ground self-defense forces with Makoto Tomita as a trainer. She then moved to the Sapporo-based Taiyō Group, which mainly operates gambling halls.
The Japanese made her international debut in 2010 in Martell in the IBU Cup . In her first race, an individual, she won her first points. It is also her best result in the racing series so far. The first major event was the Winter Asian Games 2011 in Almaty , where Mukai won the bronze medal together with Fuyuko Suzuki , Itsuka Owada and Natsuko Abe in the relay competition.