TOKYO, July 21 (Reuters) - Ivica Osim was formally unveiled as Japan's new coach on Friday and immediately asked how long his honeymoon would last.
The former Yugoslavia coach took over from Brazilian Zico, who stepped down as planned in the wake of Japan's disappointing first-round exit at the World Cup.
'It's like getting married,' a nervous-looking Osim told reporters. 'At the start the honeymoon is sweet but I'm not sure how long it's going to last.
'If the Japan team were a car you could say it has temporarily stalled. We all need to get behind it and give it a push-start.'
The 65-year-old took charge following a tug-of-war between the Japan Football Association (JFA) and J-League club JEF United Chiba, where he had been manager for three years.
His appointment caused friction among JEF United officials unhappy that the JFA had made their intentions public during the Japanese pre-season.
The Sarajevo-born Osim guided Yugoslavia to the quarter-finals of the 1990 World Cup and has also had success in charge of Panathinaikos and Sturm Graz.
Japan finished bottom of their group at the World Cup in Germany last month but Osim ruled out wholesale changes for his first two matches in charge next month.
'There will be no radical changes,' he said, shifting uncomfortably in his chair as he was grilled by around 200 journalists about his thoughts on Japan's World Cup flop.
'Japan must start playing to their potential. They should play more to their strengths -- their speed and aggressiveness. We need to get them playing a more high-tempo game.'
Japan play Trinidad & Tobago in a friendly in Tokyo on August 9 before taking on Yemen at home in an Asian Cup qualifier on August 16.
Zico became increasingly prickly and sensitive to criticism during his four years in charge and Osim warned not to expect too much too soon.
'We are not going to suddenly see physically bigger players springing up in Japan,' said Osim. 'If you always set your sights too high you can end up disappointed.'
He added: 'You have to be realistic. It will take hard work from everyone involved for Japan to keep up with the top teams in the world.'