The distributions of Cs-137, Cs-134, and K-40 as well as stable Cs, K, and Sr in bran, germ, and endosperm of brown rice contaminated by fallout from the Fukushima Daiichi Nuclear Power Plant were studied. It was found that Cs-137, Cs-134, and K-40 were accumulated in germ at the highest concentration and the concentration ratios of Cs and K in bran, germ, and endosperm were approximately identical to one another, while the highest concentration of Sr was detected for bran. Possible chemical forms of the metal elements in rice grains were discussed based on their extraction behavior with water and MgCl2 aqueous solution.