The piece delves into the evolving attitudes towards ideal age differences between couples in Japan's marriage market. It discusses how traditional norms are being upended as the market sees a diminishing preference for larger age gaps. The article explores reasons behind the shift, including changing gender roles, increasing financial independence of women, and societal factors. It provides data, expert opinions, and personal anecdotes to understand this trend.

In Japan, the tradition of men marrying younger women, typically in their early twenties, while they themselves are in their late twenties or early thirties has been prevalent. This is tied to the patriarchal customs of past generations. However, as Japanese society makes strides towards gender equality and women gain more financial independence, the concepts of ideal marriage age and preferred age gaps are seeing a significant shift.

In the US and EU, age gaps in relationships and marriage vary, and the social acceptance of larger age gaps might be more prevalent. The idea of 'ideal' age for marriage or any set norms about age differences between couples are less pronounced. Changes in Japan's matrimonial market, therefore, seem to be pointing towards a direction akin to Western countries.