show Abstracthide AbstractPostfermented tea production, involving microbial fermentation, is limited to a few regions, such as China and Japan, with Japan's Shikoku region being particularly prominent. Lactiplantibacillus plantarum is known as the dominant species found in tea leaves after anaerobic fermentation of Awa-bancha in Miyoshi City, Tokushima, and Ishizuchi-kurocha in Ehime. Although a draft genome of L. plantarum from Japanese postfermented tea has been previously reported, its genetic diversity still requires exploration. In this study, we conducted whole-genome sequencing on four L. plantarum isolates from Japanese postfermented tea using a Nanopore sequencer and compared them with isolates from other sources to examine their genetic diversity. Our findings revealed that L. plantarum from Japanese postfermented tea exhibits several highly variable gene regions associated with sugar metabolism and transportation. However, we did not identify any source-specific genes or clustering within the accessory or core gene regions. This study indicates that L. plantarum possesses high genetic diversity, and the unique environment of Japanese postfermented tea does not appear to exert selective pressure on the growth of L. plantarum.