The 60-year-old called on the Asian champions to improve ahead of next year after their third defeat in a row, but insisted the tournament was a good experienceJapan coach Alberto Zaccheroni expressed his disappointment at his side's 2-1 defeat to Mexico at the Confederations Cup on Saturday.
A double from Javier Hernandez propelled the Latin Americans to a 2-0 lead, before Shinji Okazaki pulled one back with five minutes to go. The Man Utd striker subsequently missed the chance to grab a hat-trick in stoppage time, with his penalty smartly denied by Eiji Kawashima.
The Samurai Blue trainer insisted that El Tri were the better side, but nevertheless lamented the way that Hernandez managed to score two goals.
"Unfortunately we lost but Mexico were a better. They took the initiative and they stood out more than we did. However, we played well, especially in the Italy match," the 60-year-old told NHK.
"Hernandez isn't very tall but he scored against us. We changed two defenders and tried to add more pressure but we lost. It was a good experience and we saw what we need to do to improve."
Meanwhile, Man Utd's Shinji Kagawa apologised for Japan's inability to win a point at the tournament and called on the team to improve.
"We lost and felt our weakness as a team," he said.
"We're sorry for all the fans who are watching. Brazil, Italy, and Mexico are all great teams, so we have to look at those losses and see what we have to do.
"We've lost three games in a row so we have a lot to do [in the year before the World Cup]. All of us have to improve."