TOKYO (Reuters) - When police in Japan's old historic capital of Kyoto nabbed three men this summer for buying child pornography DVDs online, they made history: for the first time, someone in the country faces the possibility of jail time for possessing such material.

Japan is the only OECD nation that has not universally outlawed possession of child pornography and activists say the new, tougher local laws in Kyoto will not change that overnight.

With various manifestations of a fascination with the young and innocent as sex objects, from graphic versions of manga, or Japanese comics, to the "junior idol" industry featuring child models in bikinis, Japan has a considerable way to go to shed an image of pornographers' safe haven.

Out of Japan's 47 provinces, only Kyoto bans possession of child pornography and prescribes a jail sentence. Neighbouring Nara is the only other province to deem it a crime, but it has only financial penalties. It has arrested several people for possession of child pornography, but authorities could not give a number since several were charged with other crimes.

In 1999, Japan outlawed production and distribution of child pornography as well as possession with the intention to pass it on, and offenders could face fines and prison terms of up to five years. However, simple possession, without an intention to distribute, remains legal, except in Kyoto and Nara.

Kyoto's new ordinance that came into force in January imposes fines for possession of child pornography and introduces a penalty of up to one year in jail for buying or downloading such material.

"It will be a big wake-up call for the parliament," says UNICEF Japan spokesman Hiromasa Nakai.

But there may not be any quick action.

There is no national debate on the subject at the moment as major parties brace for general elections expected later this year. The ruling Democratic Party of Japan has reservations about extending the Kyoto law nationally, while the opposition is for it, lawmakers told Reuters.

TOO FAR

Sanae Takaichi, from the opposition Liberal Democratic Party, says the initiatives taken in Nara province, and later in Kyoto, inspired her to campaign for a possession ban at the national level.

"I've been trying to bring such local initiatives to state politics since Nara, my hometown, put the ordinance into effect following a tragedy in the prefecture where a little girl was killed by a child porn lover."

The Democrats, however, have argued that local initiatives were going too far and making owning child pornography a crime could lead to abuse of police powers and that investigators should focus on those who make and distribute the material.

They have also voiced concern that a blanket ban could be extended to comics and animation, which in turn could infringe on the freedom of expression.

A rare endorsement for tougher laws from Japan's National Police Agency (NPA), which usually avoids positions on legislation and policy, could however help revive the debate.

The NPA says child pornography is spreading on the internet at an "unprecedented pace" so those who buy and possess it should be severely punished to curb its supply.

"Child pornography producers are making DVDs because there is demand, yet we are not able to arrest buyers," the agency said. "Furthermore, some makers are encouraged by paedophiles to make increasingly brutal products that involve rape of children, and thus such buyers should be prosecuted as heavily as possible," it said in a written response to queries from Reuters.

Police data show a steady rise in cases of child pornography production and distribution -- there were a record 1,455 cases in 2011, up 8.4 percent from 2010. This year is likely to be another record with 1,016 cases by the end of July, nearly a 10 percent rise.

There is no comparable international data, but the latest U.S. State Department human rights report describes Japan as an "international hub for production and trafficking of child pornography."

The report also says the lack of a ban on possession of child pornography in Japan "continued to hamper police efforts to enforce the law effectively and participate fully in international law enforcement."

A 2002 cabinet office survey showed that 15 percent of Japanese men polled have seen child pornography and 10 percent admitted to owning it.

In Kyoto's landmark case, police checking for illicit content online found a site selling DVDs featuring girls under 13, a local police spokesman said. Through transaction records they found the buyers: two 20-year old students and a 19-year-old office worker, who were brought in for questioning and now await charges. Their names have not been released.

LEGISLATIVE LIMBO

Advocates say only by bringing national laws into line with other major nations can Japan join the global crackdown against child pornography's rapid spread over the Internet.

Russia is another exception, where production and distribution is a crime, but possession remains legal.

Japan signed a UN protocol in 2005 that bans all forms of involvement in child pornography, including its possession, and a 2007 government survey showed 90 percent of the Japanese public favoured tougher laws.

Yet a 2008 draft law and its later versions got stuck in a legislative limbo amid frequent government changes and political trench warfare in a divided parliament.

The resistance came from lawmakers, many in the Democratic party that won power in 2009, who feared the laws could be abused to frame political opponents and only proposed punishing those who buy the material "repeatedly". Japan's bar associations also opposed the possession ban, concerned it would give police too much leeway.

"There is the possibility that the police will use this law to investigate further into different cases that are completely unrelated to the possession of child pornography," said Yuri Kawamura, a lawyer representing the Japan Federation of Bar Associations, an umbrella group.

Keiji Goto, a police officer-turned lawyer who campaigns for tougher laws, dismisses such concerns.

"It's for the sake of the children, not the police's investigative powers," says Goto, who until 2005 investigated child pornography while in charge of a cyber crime unit.

"If simple possession is illegal there will be less people buying and selling it, and as a consequence, there would be fewer victims of such abuse."