Katanec showed his respect for local tradition by attending a news conference barefooted.
"I was told to leave my shoes outside. It's the custom here," the coach, who played for Yugoslavia in Italia 90, said.
And Japanese journalists have been impressed by the ability of the Slovenians to adapt to the Japanese way.
"We are all a bit confused, but we'll get used to it," Mladen Rudonja declared.
Zeljko Milinovic, of the J-League side JEF United, predicted: "We'll probably need up to a week to completely adapt."
The only injured Slovenian player in Mimasaka, central defender Marinko Galic, is said to be progressing well.
"He has a thigh muscle problem," team doctor Vasja Kruh explained. "We're observing him closely.
"The chances are that Marinko will be fully fit for our first match against Spain."
Slovenia play their first match in group B on 2 June.