Aguirre is under investigation for match-fixing in La Liga during his time as Real Zaragoza's coach but the 56-year-old denies there is anything to the allegations, while he insists his Japanese squad are not worried about the situation ahead of the Asian Cup, which begins on January 9.
Instead Aguirre is convinced his squad - which he named on December 15 - has no excuses for not performing when they begin their campaign against Palestine in Newcastle on January 12.
"We have time, we have qualified the players. We have everything we need to win the title," he said.
Before Aguirre took over in July, Japan struggled at this year's World Cup, scoring just two goals as they finished bottom of Group C with one point.
Under their new coach, Japan have won four friendlies and lost two - against Uruguay and Brazil.
Having not lost to a continental rival since a 2-1 defeat at Jordan in March 2013, Aguirre argued it is right for his team to aim for back-to-back titles.
"It won't be easy. There are other strong teams but Japan want to win the title again," he said.
Japan have suffered a blow in the lead-up to next month's tournament, however, with Schalke defender Atsuto Uchida pulling out to focus on recovering from a long-term knee injury.
Aguirre said the 26-year-old will be missed.
"It is a shame, because he is a very important player for the national team," the Mexican said.
"But we have to think about his health too."
