Impacts of introduced largemouth bass are widely known in Japan, though previous studies have mainly focused on its impacts on fish and benthos communities. However, top predator species are also known to serve negative effects on plankton primary producers though trophic cascade effects, and hence some piscivorous fishes have been used to control primary productions in freshwater environments (i.e., bio-manipulation). We examined the cascade effect of largemouth bass, introduced from northern America into Japanese ponds together with its prey fish, bluegill, on plankton production by comparative surveys in 22 ponds in central Japan in summer of 2010. Regression analyses detected the positive effect of the presence of these introduced fishes (largemouth bass and bluegill) on the amount of phytoplankton (chl. a), in addition to the effect of total phosphorus amount (positive) and pond size (negative). Moreover, the ratio of crustaceans, which is known to be preferably utilized by bluegill, in zooplankton was decreased when the introduced fishes are present. These results suggest that the increase of phytoplankton occurred probably through the cascading effect of zooplankton predation by bluegill. Our study showed that largemouth bass, introduced with its prey, serves a contrary role against bio-manipulation effects on the primary production.