Japanese Prime Minister Fumio Kishida on Tuesday remained cautious about legally recognizing same-sex marriage and allowing married couples to take separate surnames, as opposition lawmakers grilled him on issues ranging from the economy to gender equality at the start of an extraordinary parliamentary session.

Same-sex marriage is a matter "that largely depends on individual views of what constitutes family," Kishida said, responding to a lawmaker of the main opposition Constitutional Democratic Party of Japan who urged the swift legalization of such a system.

Many members of the ruling Liberal Democratic Party, which Kishida heads, have opposed same-sex marriage on the grounds they cherish traditional family values.

Japanese Prime Minister Fumio Kishida speaks at a House of Representatives plenary session in Tokyo on Oct 24, 2023. (Kyodo) ==Kyodo

While the Diet in June enacted legislation to promote the understanding of sexual minorities, Kishida signaled that his stance on same-sex marriage has not changed.

"It is necessary to pay close attention to debates in the Diet, lawsuits on same-sex marriage," as well as moves by local governments to introduce programs recognizing same-sex partnerships, he said.

On another hot-button issue, the prime minister said there are still "various opinions in the public" over permitting separate surnames for married couples and called for more discussions to win "broad" support for the issue.

Kishida was taking questions from the representatives of each party following his policy speech delivered on Monday. The extraordinary Diet session was convened on Friday.

Japan is the only Group of Seven nation that does not legally recognize same-sex marriage or civil unions.

Japan's Civil Code requires that married couples share the same surname, with the overwhelming majority traditionally choosing the husband's name.

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