Nearly a year after returning to power, Japan's Prime Minister Shinzo Abe is on a roll. His economic stimulus policies known as Abenomics have earned praise from investors and global policy makers, his active engagement in diplomacy has impressed voters, and his approval ratings have remained consistently high. He is increasingly likely to hold on to his job for several years, an achievement that has escaped a series of his short-tenured predecessors.

To get to know the powerful leader better, The Wall Street Journal recently...