TOKYO—Japan’s stock market has surged and luxury cars are selling fast in Tokyo after eight years of economic stimulus under Abenomics, but that new wealth is concentrated in a small slice of society rather than broadly distributed, data show. Addressing that divide has become a high priority for new Prime Minister Fumio Kishida, who promised to tackle income disparity made worse by the pandemic. But he has offered few clues as to how he will do so. “It’s like everyone has become poor,” said Masanori Aoki, 62, who owns a small coffee shop in a working class district of northeast Tokyo. “With Abenomics, the finance minister talked about wealth trickling down. But there was no such thing, was there? Almost nothing,” said Aoki, who took a job as a part-time kindergarten bus driver when the pandemic-related lockdown forced him to temporarily shut down his shop. Kimie Kobayashi, 55, who works …