Wednesday marked the first time Constitution Day -- commemorating the day the document was put into effect in 1947 -- coincided with lawmakers locking horns over whether to change the sacred charter.
Although they have no authority to propose legislation, two parliamentary constitutional research panels set up in both houses of the Diet in January have so far held several study sessions and rounds of discussions.
However, full-fledged debate over whether the Constitution should be amended is unlikely to begin in the near future because lawmakers are still busy debating concepts and a general election looms.