After decades of deflation, Japan's economy looks poised to finally turn a corner. For its biggest banks, however, there's a hitch: A generation of professional front-line staff have little experience with rising interest rates.

Lenders in the world's third-largest economy are now giving crash courses to younger staff to help clients navigate higher interest rates as many of these employees have no expertise in dealing with the vagaries of a traditional inflationary environment.

The historic shift to an inflationary environment from decades of falling prices that stretch back to the 1990s presents something of a wake-up call for Japan's major banks, senior bankers say in private, warning that lenders need to change the mindset of their staffers or risk losing out on opportunities.