Distractions such as the cherry blossom-viewing party as well as the money and gift-giving scandals of ministers have resulted in Japanese Prime Minister Shinzo Abe's failure to make any advancement in his long-cherished constitutional reform plan during the extraordinary Diet session, experts said, adding that although the Japanese leader showed great confidence, it is unlikely that he will attain the goal during his current term in office as the clock is ticking away.

"The controversies brought about by the cherry blossom-viewing party and scandals that led to the resignations of two Cabinet members have overshadowed the extraordinary Diet session, leaving no space for Abe to carry out serious debates over constitutional reform," said Liu Qingbin, a professor at the Institute of Advanced Sciences at Yokohama National University.

On Monday, Japan's Diet wrapped up its latest 67-day extraordinary session, which started on Oct 4 with Abe's call for a serious debate on constitutional reform.

During the session, Japan's Diet passed 14 government sponsored bills, including a new Japan-US trade deal, but failed to advance debates on constitutional reform due to divisions among the lawmakers.

Speaking at a news conference after the session, Abe said he would seek to continue the debate "step by step" in the next session starting in January, and to lay the groundwork for the first revision to Japan's Constitution.

However, Liu said Abe's ambition would be hard to achieve because amending Japan's war-renouncing Constitution remains a divisive issue in the country, and given that Abe is set to complete his term in September 2021, there is only slim possibility of this happening.

"Changes to Japan's Constitution require a majority of two-thirds in both houses of the Diet followed by a majority vote in a national referendum," Liu said.

"As Abe failed to retain a two-thirds majority in Japan's Upper House election on July 21, he will need to sway members from outside his coalition to win approval for any amendment, which is a very hard thing."

Echoing Liu, Yu Qiang, an assistant professor at the University of International Relations in Beijing, said that although support for constitutional reform is growing in Japan, the opposition to this is strong.

"Many recall how Abe knowing that direct amendments were not viable, tried to reinterpret Article 9 of Japan's Constitution through a Cabinet decision in 2014, followed by its implementation through a national security legislation, which allowed collective self-defense among other things," Yu said.

"Tens of thousands of people protested against this on the streets at that time, and even today, the vast majority of constitutional scholars in Japan, apart from several former justices of Japan's Supreme Court say that the reinterpretation was illegitimate and unconstitutional."