Mihoko Nakayama's Eldest Son Renounces Inheritance, Sparking Japanese Parliament Debate on Inheritance Tax

According to Nikkan Sports, Mihoko Nakayama passed away on December 6, 2024, at the age of 54. Kiyoka Shioiri stated that some media reported Nakayama left an inheritance of approximately 2 billion Japanese Yen (about 400 million New Taiwan Dollars), but her eldest son chose to renounce the inheritance, believed to be due to an inheritance tax as high as approximately 1.1 billion Japanese Yen.

Shioiri questioned Finance Minister Satsuki Katayama, saying: "I believe the Minister is also aware that Ms. Mihoko Nakayama's son has renounced an inheritance of 2 billion Japanese Yen, and the inheritance tax is said to be as high as 1.1 billion Japanese Yen. Recently, public concern about the excessive burden of inheritance tax has significantly increased."

Japan's inheritance tax is a progressive tax system where the tax rate increases with the amount of the inheritance (taxable inheritance total) after deducting the basic exemption. It is 10% for amounts under 10 million Japanese Yen (zero exemption); 15% for 10 million to 30 million Japanese Yen (500,000 Japanese Yen exemption), gradually increasing with the amount; and for amounts exceeding 600 million Japanese Yen, the basic exemption is 72 million Japanese Yen, with the highest tax rate reaching 55%.

Furthermore, inheritance tax must be paid in a lump sum in cash within 10 months of inheriting the assets. Therefore, if the inheritance includes assets difficult to quickly convert into cash, such as real estate or copyrights, one often faces the situation of having to sell assets or borrow money to pay the tax.

Shioiri pointed out that there have been cases where some real estate quickly entered the market and was acquired by foreign capital. This not only leads to vacant housing issues but also has foreigners specifically targeting such real estate and writing operational guides. She questioned whether the current system is inadvertently accelerating the outflow of Japanese domestic assets overseas, which is a cause for concern.

In response, Deputy Finance Minister Shoji Maetachi stated that while Japan's inheritance tax has a top rate of 55%, which appears high on the surface, the overall system employs an 8-tier progressive tax structure, and the actual average burden rate is about 14%.

He explained that the UK adopts a 40% flat tax rate system, and while the lowest tax rate in the US is 18%, higher than Japan's, it allows for a very high basic exemption exceeding 2 billion Japanese Yen. Different countries have different systems, making simple comparisons difficult.

Regarding the official explanation, Kiyoka Shioiri noted that the problem with Japan's system is that its taxable scope is broader than in countries like the UK and US, extending not only to high-asset individuals but also to the middle class.

She stated that there has long been criticism that inheritance tax and income tax might constitute "double taxation." Although the Japanese government explains that taxes are levied based on the heir's ability to pay, public acceptance remains very low.

Shioiri urged the Japanese government to continue strengthening supervision of foreign capital acquisitions under the Foreign Exchange and Foreign Trade Act and to fundamentally review the inheritance tax system, assessing whether there is room for adjustment to prevent the tax system from inadvertently accelerating the outflow of domestic assets. (Editor: Chen Yen-chun) April 10, 2026