Beginning of the War
While Don Salvatore was in prison in the police station in Pike Creek, Shoreside Vale, the Yakuza were moving to Liberty City. They were stocking up on heavy weapons, including a Rhino. Toni was sent by Salvatore to steal the Rhino and destroy it. After that attack. the wife of the Yakuza waka-gashira, Toshiko Kasen, called Toni and asked him to destroy her husband and his organization. This was the beginning of many attacks that would severely weaken the Yakuza.
Her first request was to steal Yakuza weapons and bring them back to a weapons dealer waiting in Rockford, Staunton Island. Her second request was to attack one of the Yakuza's trucks with a large amount of money and burn the money. Kazuki became aware of his attacks as he saw Toshiko and Toni going to the opera in Fort Staunton together. Kazuki was gathering his men to kill Toni, but Toni got to Big Shot Casino in Torrington, Staunton Island and got into a sword fight. Toni managed to kill Kazuki and gave his sword back to a regretful Toshiko as she committed suicide by falling purposely backwards of her window.
It is possible an attack not mentioned in game took place, making them even more hostile towards each other. The attack could of went as follows:
‘Cash in Kenji’s Chips’
As the Leone’s turned bored of having little influence in Liberty and wanted to branch out; they needed some influence on Staunton thought Salvatore as he stared at the sun peering through the blinds, thinking of how much influence the Forellis had on Staunton and and Shoreside. There had to be a change thought Salvatore; the Yakuzas he thought, that was it - Kenji. If they could get a stronghold on the casino and take out Kenji, the whole of Torrington would be theirs.
The Leone convoy got ready to cross the Callahan bridge as they did Salvatore had a invincible feeling come over him. They travelled through Bedford point pushing inwards towards the Yakuza fortress. They were feeling optimistic and some of the Leone gang members started singing Italian folk songs. They chose the Yakuza to avoid any bad blood with the Forrellis during their territory battle with the Columbian Cartel and after the loss of their don - Franco Forrelis at the hands of Salvatore’s main man Tony Cipriano. And the Yakuza were about to lose their waka-gashira or so he thought.
The man himself Tony Cipriano was not with them instead he was told to be on high alert in case the Yakuza launched a counter attack on Saint Mark’s in retaliation the Leones were distracted. The Leones were reaching the casino. He saw a Yakuza on the pavement he told his driver to run him over. It was a trap - he thought, someone must have snitched. The Yakuza were somehow waiting for them with snipers on the roof; they had been set up. He pulled up unexpectedly to see Kenji himself with two Yakuzas beside him. He said ‘I believe we have mutual business to discuss, mr. Leone.’’Screw you!’ Salvatore panted as he raised his shotgun and they exchanged fire with Kenji’s bullet skimming past Salvatore’s left shoulder and hitting the rear lights of the leone sentinel they were driving. Salvatore had made a deal with the Southside Hoods to help them storm the casino in exchange for any narcotics in within the compound. More Leone cars arrived as they were swiftly blowed up by Ken with an RPG on the balcony. Ken travelled to the helipad to get a view of the Leone cars pulling in the driveway to go in the side entrance and sneak in the back entrance; once Ken blew up these cars his attention was drawn to Southside Hoods traveling through the south-east forest area with sniped rifles. He saw a briefcase he dived to it amongst the hail of gunfire. He jerked it open to find a sniper rifle, he kneeled behind the railing and fired - popping off the heads of the African-Americans. Meanwhile casino security and Kenji’s protection squad rushed out of the building with uzis; just realising how bad the situation was. Asuka was contacted by the casino and she was told not to leave her condo. As the guards came out Kenji ran in the casino.
Ken looked to his left to see more Leone cars coming, he grabbed his rocket launcher and fired; wiping out the gang cars. The last wave he though a convoy at six Leone Sentinels looking to be sandwiching Mickey Hamfists who got out of the vehicle and fired a rocket at Ken; however he dived out the way before blowing up all Leone cars bar one. Everyone down there hit the floor including Salvatore. As more Yakuza came from down the street and the two other streets the remaining Leones were trapped. Mickey Hamfists got in the vehicle and as more Yakuza came from their patrol and from the casino Salvatore got in the car and said ‘Get me the hell outa here!’ and the Leone car went speeding down the road. The attack had failed.
By 2000, the setting of GTA Advance, Asuka got her revenge when she orders Mike to kidnap 15 supposedly Leone members (still uncertain but seems most likely.) and she would sell them back to Asia as slaves. By 2001, the setting of GTA III, she met former Leone ally Claude and asked him to cut his ties with him and order the death of the Leone Don Salvatore Leone. Claude killed Don Leone and then kills a number of Leone hitmen disguised as FBI agents sent to assault the Yakuza territory. Despite this, Salvatore's death doesn't seem to weaken or defeat the Leones as his position was possibly taken over by Caporegimes Toni Cipriani and Joey Leone. The Leones also stock up more powerful weaponry as evidenced by their shotguns used to attack the player once he/she reaches Saint Marks.