Japan's ruling Liberal Democratic Party (LDP) and its junior coalition partner, Komeito, last month achieved an overwhelming victory in the Upper House election. The pro-revisionist camp now accounts for two-thirds of the seats, and because of this, some people think that efforts to revise the Constitution will move forward.

This majority theoretically could enable the coalition to initiate a national referendum on amending the Constitution and its sensitive, war-renouncing Article 9. But will the coalition in fact do so?

Japan has not revised a single word of the current Constitution that was enforced 70 years ago on May 3, 1947, in the aftermath of the country's defeat in World War II. One could argue that this is because the anti-revisionist camp, which fully opposes revising the Constitution, has held the pro-revisionist camp in check.

An opinion poll by the Mainichi newspaper in May shows that when it comes to revising the Constitution, those in favour and those against are neck and neck, with both groups accounting for around 40 per cent each. That indicates how cautious the public is when it comes to the issue of Constitutional revision.

The institutional approach to revising the Constitution in Japan is this: Japan's Diet is a bicameral system consisting of the Lower House and the Upper House, with the Lower House being the dominant of the two Houses. However, neither House takes precedence over the other when it comes to revising the Constitution. The issue of revision can be brought up at the Diet, and it is stipulated (in Article 96 of the Constitution) that at least two-thirds of the members of both Houses must vote in favour of revision.

A soldier with the Japan Maritime Self-Defence Force training alongside US Marines in Hawaii last month. Japan's ruling Liberal Democratic Party and its junior coalition partner Komeito hold a two-thirds majority in Japan's Diet, and could initiate a referendum on amending the Constitution and its sensitive, war-renouncing Article 9. However, it is unclear whether or not the coalition will actually do so. PHOTO: REUTERS

After that, the issue of revision is put before a national referendum, or some other type of similar vote. In order for the Constitution to be revised, a majority of people must vote in favour of doing so. This is a very stringent condition.

The Upper House has 242 seats, and the members serve six-year terms. Half of the members are replaced every three years. In the recent Upper House election, the voting age was lowered to 18 years.

The election turned out to be an overwhelming victory for the ruling coalition, with the LDP gaining six seats, while the Democratic Party (DP), the largest opposition party, lost 15 seats. As a result, the parties in favour of revising the Constitution now control two-thirds of the seats in the Upper House.

In the Lower House, the LDP holds 290 of 475 seats, while Komeito holds 35 seats, indicating that the pro-revisionist camp already accounts for more than two-thirds of the Lower House. Thus, the results of the recent Upper House election mean that the pro-revisionist camp now holds a two-thirds majority in both houses.

The outcome of this election raises the question: Why do people who are cautious about revising the Constitution vote for parties or persons in favour of doing so? This is a point that other countries cannot really understand. In the news, revising the Constitution was regarded as a focal point of the election, and thus the victory of the pro-revisionist camp in Japan tends to be interpreted as a sign that Japanese society is leaning towards the right.

However, as the Mainichi opinion poll shows, Japanese society as a whole is still cautious about revising the Constitution. This means that voters are not unequivocally swayed by the position of the parties and candidates when it comes to the issue of Constitutional revision. The main issues for voters in the latest election were ultimately social and economic in nature.

According to an Asahi Shimbun exit poll, economic and employment measures were the top concern for 28 per cent of voters, followed by social security (15 per cent), the Constitution (14 per cent), child support (13 per cent) and consumption tax (11 per cent).

It would seem that many voters decided on candidates based on their economic views. An opinion poll conducted by NHK also found that 56 per cent of voters have a positive view of Abenomics.

Going forward, I assume that the Abe administration will begin preparations for revising the Constitution in consultation with the DP. The first step will be discussions by the Constitutional Research Council in both Houses. However, given that the term of office of Prime Minister Shinzo Abe will expire in 2018, it is unclear whether the administration will make it to the actual revision stage within his final two years in office.

There is grave concern outside Japan that revising the Constitution means amending Article 9. This concern is not unfounded, for there are those in the pro-revisionist camp who are in favour of such an amendment.

However, the Japanese public is cautious about making any change to Article 9. In addition, those in favour of its revision also include those who want it amended to impose even stricter restrictions on Japan's use of military power. They do not approve of the changes made to the interpretation of Article 9 by past administrations, and would rather give Article 9 clear statutory form with no room for interpretation to prevent the government from further extending its present interpretation. This faction is proof that the pro-revisionist group is not entirely conservative.

In this respect, I am afraid that arguments in Japan about revising the Constitution are extremely difficult for people in other countries to understand. It is true that last month's Upper House election may have opened the way to revising the Constitution, but this result alone does not immediately lead to the amendment of Article 9. It is important for readers to understand that this issue is still at the stage where careful deliberation needs to be carried out.

• The writer is a professor at the Graduate School of Arts and Sciences, the University of Tokyo.