When ORIX launched its Growth Strategy 2035 just over a year ago, some observers wondered whether the targets - a 15% return on equity and 1 trillion yen in net profit - were more aspiration than plan.

For more than 60 years, ORIX has been one of Japan's best-kept secrets: a widely diversified and quietly formidable corporate group that has expanded across industries and continents while remaining, to much of the international investment…