TOKYO - Satoru Nomura has been called "God" and "Emperor" by his underlings, who would wait on him 24 hours a day in a palatial compound in Fukuoka.

But the 74-year-old head of Japan's most violent yakuza gang, often seen in spiffy bespoke suits, and chauffeured around in a Mercedes-Benz, will now have to swop his luxurious surroundings for a jail cell to await possible execution.

Nomura was sentenced to death on Tuesday (Aug 24) for the murder of a civilian and attempted murder of three others between 1998 and 2014. His No. 2, Fumio Tanoue, 65, was given life behind bars.

"You'll regret this for the rest of your life," Nomura, who had been composed throughout the trial, let rip at Presiding Judge Ben Adachi upon hearing his verdict and sentence. "I asked for a fair judgment, but this is not fair at all. Where's the proof?"

Tanoue, meanwhile, called the judge an "awful person".

Local police are not taking the threat lightly, and have beefed up protection for the judge, prosecutors and witnesses given the yakuza's penchant for exacting revenge.

"When stripped of their armour, syndicate leaders reveal their true selves: cunning, devious, and depraved individuals who grasp at dominion and use murder as a tool to eliminate all who oppose them in a quest to acquire what makes them feel whole," criminologist Enzo Yaksic told The Straits Times.

The mobster duo helm the Kudo-kai, the only organised crime syndicate in all of Japan to be branded a "dangerous designated criminal group" for its brutality.

The gang, based in the port city of Kitakyushu in the south-western prefecture of Fukuoka, has been accused of terrorising ordinary folk over decades and is said to be behind a spate of public assaults and extortions for "protection money".

Nomura and Tanoue have appealed what they call a "ridiculous" verdict. The process could take years, but unless he can get the verdict overturned, Nomura could eventually be headed for the hangman's noose.

Penchant for violence

Nomura was born in 1946, the youngest of six children in a rich farming family.

He spent his riches on gambling as a teenager and soon fell into delinquency. He was thrown into a juvenile home for a spate of crimes, including stealing a car.

Nomura did not graduate from secondary school, and in his 20s was co-opted into the gang by a senior member of an affiliate group of the Kudo-kai.

His wealth bankrolled the gang in crimes such as real estate fraud and illegal gambling dens, through which he reaped huge profits to the tune of an average of 30 million yen (S$368,000) per night.

He gradually rose to head the organisation, which, at the height of its influence in 2008, had about 1,210 members. This plunged to 430 members by last year.

The first of four cases tied to Nomura and Tanoue was in February 1998, when a 70-year-old leader of a fishery cooperative was gunned down in public after he refused to do business with Nomura.

This would not be the end of it. Judge Adachi noted how the grudge must have simmered as Kudo-kai struck again in March 2014, the victim this time a seemingly random dentist who was stabbed in a carpark.

But he was the grandson of the late fisherman. His fiancee's family was so shaken by the attack that the wedding was called off. The judge said this was likely an attempt to intimidate the family into submission.

These cases bookend two other assaults. In 2012, a retired police officer who had been probing Kudo-kai was shot in the leg, while in 2013, a nurse at a cosmetic surgery clinic was stabbed after Nomura was displeased by her attitude and the outcome of his operation.

The four incidents form the charges against Nomura and Tanoue, but these were allegedly not all. A series of other attacks have been tied to the Kudo-kai, including in 2003 when a hand grenade was lobbed into a nightclub in Kitakyushu, injuring 12.

Eateries that refuse to do Kudo-kai's bidding have been subject to arson. And employees of two construction firms were targeted between 2008 and 2011.

Mr Yaksic observed that leaders of criminal syndicates are often "gratified by the total submission of their victims and underlings", and would stop at nothing to eliminate obstacles to their immediate goals.

The direct perpetrators behind these attacks have all been nabbed and punished. The gunman behind the 1998 killing has been jailed for life.

But Nomura and Tanoue got away with it until now. They were first arrested in 2014 but were out on bail till Tuesday's verdict.

Unprecedented verdict

Law enforcement decided enough was enough in 2014, when police launched Operation Summit in a bid to bring the gang to its knees by "cutting off its heads".

Tuesday's verdict was the culmination of a trial that started in October 2019 and comprised 62 hearings and the testimonies of 91 people, including former gang members and police officers.

Legal experts described the case as a landmark ruling for numerous reasons, saying the judgment will impact future probes into organised crime.

Notably, there was no direct evidence connecting Nomura and Tanoue to the crimes.

They were not at the scene, but the verdict relied heavily on a concept dubbed "employer's responsibility" as inferred through the clear, hierarchical chain of command within the gang.

Judge Adachi said, in what was the first death sentence passed on a sitting syndicate boss in Japan, that it was only logical that the underlings had committed the crimes because of the "strong organisational structure in which superiors' orders must be followed".

Further, the four victims were not linked except by Nomura's personal grudges. The judge saw no question that Nomura, as ringleader, would know of the planned crimes in advance.

Also, while the death penalty can be given to convicted murderers in Japan, it is not meted out lightly and is usually reserved for serial killers.

But the judge noted the egregious nature of Nomura's crimes as he agreed that the death penalty was warranted.

"There can be no extenuating circumstances for the motives and circumstances of the organisation's attack on the regular citizens," the judge said. "The criminal responsibility is so serious that the choice of capital punishment is unavoidable."

Kyushu University law professor Koji Tabuchi told NHK: "The verdict that does not exonerate top management for a crime committed by their underlings is significant. It seems that the growing citizen awareness and desire to clean up society might have influenced the court's decision."