In Tokyo, some 60,000 people, including students, legal experts, representatives from opposition parties, as well as common citizens, rallied in the city's Rinkai Disaster Prevention Park, holding banners and flags and shouting slogans such as "Changing Article 9, No" "Abe administration should step down."
Kazuo Shii, head of the Japanese Communist Party, said at the gathering that the plan to change Article 9 of the Constitution would make it possible for Japan's Self-Defense Forces (SDF) to be involved in wars abroad and such a plan should be firmly opposed.
Toshihiro Yamauchi, professor emeritus of Hitotsubashi University, said that it's because of the pacifist Constitution that Japanese people could enjoy peaceful life and the Constitution Memorial Day provided people an opportunity to reaffirm the positive role that the pacifist Constitution has played on safeguarding peace.
Rallies were also held in Osaka, Fukuoka and Hokkaido and other areas across Japan, according to local reports.
Abe, however, reiterated on Thursday his attempts to amend the Constitution in a video message at a gathering of supporters of constitutional revision in Tokyo.
He said that "now is the time" to carry forward discussions to justify the existence of the SDF in the Constitution.
According to the organizer, some 1,200 people attended the gathering.
Japan's current Constitution, drawn up under the Allied occupation following the World War II, is best known for its Article 9, by which Japan renounces its right to wage war and promises that "land, sea, and air forces, as well as other war potential, will never be maintained."
The Constitution has never been revised since it went into effect on May 3, 1947.
Revising the Constitution has long been a goal of Abe and the ruling Liberal Democratic Party (LDP). The LDP has been advocating constitutional revision as part of its platform since the party was founded in the 1950s, including changing the war-renouncing Article 9.
Public opinions about amending the Constitution, however, remain differed. A recent poll by Japan's Kyodo News showed that 61 percent of the respondents were against any constitutional amendments under the Abe administration.