ITAMAE aims to build a community of young challengers across the country and build a foundation to grow the innovators of tomorrow. | COURTESY OF ITAMAE Tokyo is readying for its annual startup convention, SusHi Tech Tokyo — starting Monday — to bring together entrepreneurs, investors and policymakers from across the globe. But Asia’s largest startup event also highlights a quiet shift taking place among Japan’s younger generation, where in a country long associated with preference for stability and traditional career paths, an increasing number of students are turning toward entrepreneurship.…