When Warren Buffett speaks, investors listen. And when the Oracle of Omaha starts selling bonds — especially in Japanese yen — eyebrows raise across global markets.

This week, it was revealed that Warren Buffett's Berkshire Hathaway (NYSE: BRK.B) is planning to issue new yen-denominated bonds.

While that may sound like business as usual for the finance giant, it's what comes next that really matters: the funds could be used to increase Berkshire's investments in Japan's five major trading houses.

Buffett has already made no secret of his admiration for Japan's corporate discipline, shareholder-friendly reforms, and capital efficiency. Now, he looks set to take things a step further — and ASX investors don't have to miss out.

Here's how you can tap into Japan's investment revival with a couple of easy-to-access ASX ETFs. They are as follows:

Betashares Japan ETF Currency Hedged (ASX: HJPN)

If you're looking to follow Warren Buffett's footsteps with a cleaner currency exposure, the Betashares Japan ETF Currency Hedged is a great place to start. This ASX ETF provides investors with exposure to a diversified portfolio of leading Japanese companies, while hedging out the effects of currency fluctuations between the yen and the Australian dollar.

The fund tracks the S&P Japan Exporters Hedged AUD Index, which includes household names like Toyota, Sony, and Hitachi. These are companies that stand to benefit from global demand and a weaker yen.

Given Buffett's interest in Japan's global trading giants, the Betashares Japan ETF Currency Hedged offers a good way to gain broad exposure to some of the country's best-known international players.

iShares MSCI Japan ETF (ASX: IJP)

If you'd prefer to ride the yen, rather than hedge it, the iShares MSCI Japan ETF is another option worth considering this month. This ASX ETF tracks the MSCI Japan Index, offering investors access to over 200 of Japan's largest publicly listed companies. This includes financials, industrials, and consumer goods.

While unhedged ASX ETFs do come with added currency risk, they also offer the potential for upside if the Japanese yen strengthens over time. With ongoing structural reforms in Japan, rising interest from foreign investors, and a renewed focus on corporate governance, many believe the Japanese market (and the Japanese yen) still has room to run.

And if Warren Buffett's buying, that could certainly just tip the scales for some.

Overall, both ASX ETFs could be good options if you are a fan of Buffett's investment style and require some international exposure for your portfolio.