Legendary investor Warren Buffett revealed on his 90th birthday that Berkshire Hathaway (BRK.B) has invested $6 billion in Japan’s five biggest trading houses--Mitsubishi, Mitsui, Sumitomo, Itochu and Marubeni. These are giant conglomerates involved in various businesses like technology, manufacturing, convenience-store chain, energy and mining.The “Oracle of Omaha” said these stakes are a little more than 5% each currently which may be increased up to 9.9%. Berkshire, which plans to hold these investments for the long term, had planned these investments smartly. These were funded through yen-denominated bonds that carry a weighted average interest rate of 0.67 % per FT, and these companies have an average dividend yield of over 4%.A change in leadership from Shinjo Abe to Yoshihide Suga, and the possibility of snap elections have also resulted in increased interest in Japanese stocks, which are very attractive in terms of valuations.The Franklin FTSE Japan ETF (FLJP) charges just 9 basis points, whereas the most popular Japan focused ETF –the iShares MSCI Japan ETF (EWJ)—has an expense ratio of 49 basis points. The JPMorgan BetaBuilders Japan ETF (BBJP) charges 0.19%.All three ETFs track market-cap-weighted indexes and provide similar exposure. Toyota Motors (TM), Sony (SNE) and SoftBank (SFTBY) are among the top holdings in these funds.The WisdomTree Japan Hedged Equity Fund (DXJ) holds export oriented Japanese companies which benefit from a weaker yen. It hedges out the currency risk and is worth a look in case the yen moves lower.To learn more, please watch the short video above.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Sony Corporation (SNE): Free Stock Analysis Report Berkshire Hathaway Inc. (BRK.B): Free Stock Analysis Report Toyota Motor Corporation (TM): Free Stock Analysis Report Softbank Corp. (SFTBY): Free Stock Analysis Report iShares MSCI Japan ETF (EWJ): ETF Research Reports WisdomTree Japan Hedged Equity ETF (DXJ): ETF Research Reports Franklin FTSE Japan ETF (FLJP): ETF Research Reports JPMorgan BetaBuilders Japan ETF (BBJP): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report