Lake Biwa Marathon
Sato returned to the marathon in 2003 and gained selection for the World team via a personal best run of 2:08:50 minutes at the Lake Biwa Marathon (he was fifth and the third fastest Japanese). He placed third at the Sapporo Half Marathon in July and was tenth in the marathon at the 2003 World Championships in Athletics in Paris. He set a series of personal bests in 2004: 8:00.83 minutes for the 3000 metres, 13:33.62 minutes at the Oda Memorial 5000 m, 2:08:36 hours in the marathon (fourth in Lake Biwa), and finally a 10,000 metres best of 27:56.86 min in Niigata. He did not gain selection for the 2004 Olympic team. He performed to a lower standard in 2005, having seasonal highlights of a fifth-place finish in the 10,000 m Japanese trials and 16th at the Chicago Marathon. His 2006 was worse, as his only major competition was the Lake Biwa Marathon and he failed to finish the race.