There is not much similarity between modern Japanese pronunciation and Minnan dialect.

Whether Japanese belongs to Altaic language family is still controversial, while Minnan language undoubtedly belongs to Sino-Tibetan language family.

However, the pronunciation of Chinese characters in Japanese has a homologous relationship with Fujian dialect. "Wu Yin" in Japanese comes from Wu dialect in Tang and Song Dynasties, which is the most complete in Min dialect, not modern Wu dialect.