The man with the microphone is Shinichi Yokoyama, who in 2018 was the Chairman of the Judicial Affairs committee in Japanese Parliamen.
On December 8th, 2018, Japanese Parliament voted on a hotly contested immigration reform bill that allowed foreign workers a path to Japanese citizenship. The plan was put forth by then-Prime Minister Shinzo Abe earlier that year and was opposed by Japan's opposition party, as well as some in Abe's right-wing base.
When Yokoyama attempted to move to hold a vote on the controversial bill, he was beset by members of Parliament who apparently wanted to stop him from moving forward with a vote, leading to the image of Yokoyama speaking into his microphone while dozens of politicians attempted to restrain him.
It should be noted that physical altercations are not exactly a rarity in Japanese Parliament, as the group has made headlines for what some have called "brawls" in both 2015 and 2023.