Leslie spent three years coaching the top University Colts side and then another three years in charge of University A, which culminated with the side winning the title last season.
"I will get back involved in coaching but this year is where I really want to be focused on my business and that is going to take a little bit of time," Leslie said.
"I still want to be a coach and really enjoy working with rugby players. I've made plenty of mistakes over the years and got a few things right but I've learned a lot and it has been most enjoyable and rewarding."
He still plans to coach his son's under-11 side.
Leslie, the former long-serving Otago and Scotland midfield back, said the biggest change with University rugby since he played in the 1990s was players now were much more mobile.
"Nearly every student now has a car and that means they can drive out to clubs and look elsewhere. It used to be that they were living around the university area, then the only club to go to was University.
"But other clubs are now chock-full of students. You go through whole teams and students are there. And that is not just rugby. Netball, hockey is the same."
Leslie also said the University club was traditionally a slow starter as students did not drift back into town until February, while other clubs were active well before Christmas.
The club had a special history, having won 49 titles and produced 44 All Blacks - the most of any club in New Zealand. But that history meant little to a current student, Leslie said.
Leslie is being replaced by John Hyde, who coached the Colts team for two years but stood back last year. He will be assisted by Grant Sneddon.
Hyde said numbers had been picking up at pre-season training and about half the squad from last year would be back.
If players wanted to make progress in their rugby careers, University was a good club to play for as it offered New Zealand Universities tours overseas at both senior and colts level, Hyde said.
He said other clubs had been extremely well organised in the past but University could only control what it did and players would come.
