After retirement, in 1989, Miyauchi became a manager for Nadeshiko League club Prima Ham FC Kunoichi. The club won 1994 Empress's Cup, 1995 Nadeshiko League and 1997 Nadeshiko League Cup. He resigned in 1997. In 1997, he also became a manager for Japan women's national team. He managed at 1997 AFC Women's Championship and 1998 Asian Games. Japan won the 3rd place at both tournament. In 1999, he managed at 1999 World Cup. However Japan was defeated in group stage and failure to qualify for 2000 Summer Olympics. This helped to cause with economic stagnation the withdrawal of a series of teams from the Nadeshiko League. Japanese women's football was on the verge of decline. He resigned after 1999 World Cup.