Since starting Nidec in 1973 in a tiny Kyoto shed with just three workers, Shigenobu Nagamori has built it into the world's top maker of precision motors and became one of Japan's most venerated business leaders.

Nagamori guided Nidec past Nissan and Panasonic in market value, and helped place its products in everything from cars to smartphones. But the 74-year-old now faces what may be his hardest task: passing on the reins.

Analysts say it will be particularly tough at Nidec, where employees and investors are enthralled by Nagamori's vision, outsized personality and brash confidence.