Here is a place in Japan where business sentiment is higher than it was in the era of the bubble economy in the late 1980s — Okinawa, the string of islands known for crystal-clear waters and white-sand beaches.

Businesses in Okinawa were more confident in September than at any time since 1974.

The prefecture, which is closer to Taiwan than to Japan's main islands, saw the number of foreign tourists surge. The 6.5 million domestic and foreign tourists are a boon for businesses like hotels, cafes and restaurants in Okinawa's services-dominated economy.

Foreign tourist numbers in Okinawa rose 63 percent in the 10 months through October from the same period in 2014, outpacing the nationwide gain of 48 percent, according to figures by the prefectural government and the national tourism organization.

The growing confidence in service sectors from robust inbound spending has contributed to the "unusually high level" in Okinawa, according to a report written by Kentaro Koyama, economist at Deutsche Bank AG in Tokyo.

While business confidence in Okinawa is outpacing other areas, the disparity in sentiment among regions, excluding Okinawa, is narrowing, and the gap in sentiment among industries is narrowing, according to an analysis by Koyama. Those suggest that the positive impact of Abenomics is spreading steadily to regional areas, he said.