This study aimed to elucidate the characteristics of the flower-visiting insects community in the coast of western Japan (Pacific side). In total, 144 individuals belonging to 27 species were collected from the flowers of three coastal plants, Lathyrus japonicus, Calystegia soldanella, and Vitex rotundifolia, as well as from Senecio madagascariensis, an invasive alien species. We compared our results with those of previous studies, which reported that Apis mellifera was the most abundant insect species. It was found to be the dominant species on L. japonicus and C. soldanella. The findings on the flower-visiting insects found on L. japonicus were not consistent with those of previous studies. Some common flower-visiting insects were found on C. soldanella in different areas. The main flower-visiting insect on V. rotundifolia was Megachile kobensis, consistent with the results of two previous studies. M. kobensis is regarded as a particularly important flower-visiting insect. Although the nectar of its source plant decreases toward the end of May and from September to November in the study area, during this period, the beach may possibly have little nectar of resources for visiting-insects.