Correction: An earlier photo caption misidentified dairy farmer Hidehisa Takemura. This version has been updated.

Hidehisa Takemura, 44, a dairy farmer in Kochi Prefecture on June 21, 2013. The population of this rural prefecture drops by 5,000 every year, and some in Kochi fear a cycle in which Tokyo cuts down on political representatives from the countryside and those areas, in turn, decline all the faster. (Chico Harlan/Washington Post)

This isolated southern prefecture has no bullet trains or teams in the top professional baseball leagues. Its highways stop well short of the coasts. Only one company here is listed among the 1,700 blue chips on the Tokyo stock exchange.

But Kochi prefecture, a mountainous outpost for aging fruit and vegetable farmers, ranks among the most politically powerful places in Japan.

Kochi and other rural regions are granted disproportionate power under a national electoral system that analysts describe as antiquated and that Japan’s Supreme Court says is “in a state of unconstitutionality.” Under the system, rural areas are allotted more representatives in parliament than they ought to be based on their share of the national population. As a result, voters in rural areas such as Kochi carry more than twice the weight of those in Tokyo or Sapporo.

The imbalance is decades old, but it is intensifying as ever more people drain from the countryside into cities. It also leaves Japan with an increasingly problematic mismatch — a rigid and conservative political system for a country seeking ways to reform. The power of older, largely change-resistant rural voters acts as a head wind as Prime Minister Shinzo Abe ponders ways to revive Japan’s economy and clear its enormous government debt.

Rural and urban areas have little agreement on what’s best for Japan, a key fissure in a country that overwhelmingly supports a single party — the Liberal Democrats. The Liberal Democratic Party’s grip on power figures only to strengthen after July elections for the upper house of parliament, but the LDP’s lawmakers from rural and urban areas often fight for conflicting issues.

The priorities of those in Kochi are “completely different” from those in an urban area, said Yuji Yamamoto, an eight-term Diet member who represents a district of Kochi prefecture in the lower house.

Those in rural areas say the government should protect the agriculture industry and social security spending, two key sources of their livelihood. But some economists argue that Japan’s agriculture industry — a patchwork of small plots that produce high-quality but pricey goods — should be overhauled as part of a free-trade agreement that knocks down astronomical tariffs. The economists also say that Japan — whose population is aging more rapidly than any in the world — must slash pensions to keep pace.

“This over-representation of the elderly makes returning to a sustainable fiscal path very difficult,” Robert Feldman, Morgan Stanley’s chief economist for Japan, wrote in an April research report.

Courtroom wrangling

The disparity between rural and urban voters stems from the mass migration that began nearly seven decades ago and is going strong. After World War II, nearly two-thirds of Japanese people lived in the countryside. Today, by some measures, the figure is less than one-fifth. Japan’s voting system has gone through reforms, but the outlay of parliament seats hasn’t kept up with the population shift.

The system is complicated, and in both houses of parliament, a minority of seats are filled proportionally — that is, based on each party’s share of the vote. But the other members are voted in by winning contests in their back yards.

In the upper house, candidates represent their prefecture, equivalent to a state. Every prefecture sends at least two members to the Diet. None sends more than 10. The number of representatives differs from prefecture to prefecture by population — but it doesn’t differ quite drastically enough. Rural Tottori has about 240,000 voters per representative. Tokyo has more than a million per representative.

The imbalance in the more powerful lower house isn’t nearly as drastic, but it lately has been the subject of more courtroom wrangling. In the lower house, the nation is carved up into 300 districts — each of which sends one member to the capital. The rural districts are geographically larger but not large enough: A vote in Yamamoto’s Kochi district counts about 2.4 times as much as a vote cast in Chiba, on the outskirts of Tokyo.

In 2011, the Supreme Court ruled the results of a 2009 election — and thus, the electoral system itself — to be in a “state of unconstitutionality” and recommended that policymakers redraw districts. It also threatened that any subsequent election could be ruled invalid. A parliament advisory panel said the disparity should fall below 2.0.

A December election was held without any changes to the electoral system, spurring activists and civic groups to file more than a dozen lawsuits in local courts. Two of those local courts ruled the election results invalid — decisions that will play out in higher courts this year.

But lawmakers have barely budged, and analysts say they are loath to upend a system that would cost some of them jobs. One bill, passed into law Monday with the support of the LDP and a smaller coalition party, calls for cutting lower house seats from five districts, including in Kochi prefecture. Such tweaks are designed to lower the vote disparity to 1.998, but given the urban drift, the legislation could be outdated by the time it takes effect.

“Already the latest census shows the voting disparity will be above 2,” said Koichi Nakano, a political science professor at Sophia University. “They’re doing the bare minimum, not even the bare minimum.”

Breaking the cycle

The power of rural Japan feels egregious only when viewed from outside its confines. In Kochi prefecture, voters scoff at the idea that they have power: They’ve instead watched, powerless, as their population drops by 5,000 every year and as mountainous towns empty out with no realistic plans for revival.

They say they feel far removed from decisions made in Tokyo, particularly Abe’s commitment to join the Trans-Pacific Partnership, a massive free-trade agreement that includes agriculture giants such as Australia and the United States. Japan is likely to push in negotiations for protection of certain agriculture products — notably rice, wheat, beef and pork — but most of the other goods, such as those made in Kochi, will be open to foreign competition.

“If we proceed with this kind of reform, there will not be people in rural areas anymore,” said Shigeyuki Tanouchi, the Kochi regional manager of JA-Zenchu, Japan’s massive agriculture co-op.

Some in Kochi fear a cycle in which Tokyo cuts down on political representatives from the countryside and those areas, in turn, decline all the faster. Analysts say that, in theory, there is an alternative solution to Japan’s electoral disparities: The rural areas could gain back population.

Hidehisa Takemura, 44, moved back to Kochi 14 years ago, leaving his sales job at a metal manufacturer in Tokyo. He settled back into his family’s dairy farm, tending to a barn of 1,300-pound Holsteins. He also started voting more, compelled by the issues facing his region.

“In Tokyo, you can live comfortably and the problems feel distant,” he said. “Whereas here, it’s a different situation.”

Yuki Oda contributed to this report.