The American musician accused of killing young Irish exchange student Nicola Furlong has denied he murdered her on the first day of his trial in Tokyo, Japan.

According to the Irish Times, Richard Hinds, 19, a musician who was touring Japan and who comes from Memphis, Tennessee admitted to lightly pressing Furlong's neck in his hotel room, after what his defense team called 'rough sex.'

'I do not believe I was the cause of her death because the pressure was too light,' Hinds reportedly told the Tokyo District Court. 'I had no intent, motive or reason to hurt, harm or kill her.'

But the prosecution said Hinds used a bath towel to strangle Furlong shortly after 3AM on May 24 last year. A towel found in the hotel room contained his DNA, the court heard.

Furlong's blood also tested positive for the sleeping drugs Xanax and Lidocaine, the prosecutors told the court. They believe Furlong, from Curracloe, County Wexford, and her Irish friend were drugged after meeting Hinds and another American man outside a rap concert.

'The defendant shows absolutely no remorse,' said lead prosecutor Kenji Horikoshi, demanding 'harsh' punishment. Hinds faces up to life imprisonment if convicted.

Hinds' defense team argued that there was 'no proof' of murder and a 'strong possibility that the victim died from ingesting alcohol or drugs.'

Furlong's parents, Angela and Andrew, reportedly looked directly at the accused throughout yesterday’s session. Their daughter Andrea and several Irish friends sat in the public gallery.

Nicola, an international business student in Dublin City University, was studying at the Takasaki City University of Economics at the time of her death.

On the night of her murder, she and another Irish friend had travelled to central Tokyo to attend a concert by US rapper Nicki Minaj.

In court yesterday Angela Furlong wiped away tears as the defense read out their opening arguments, alleging that the Irish student had demanded sex in the defendant's room in the Keio Plaza Hotel and had grown aggressive when he refused. The defense said Hinds put his hand over Furlong's face and neck when she shouted at him, but he had not intended to kill her.

Takuya Niwano, the hotel's duty manager, told the court he found Furlong's body on the floor of Hinds’s room at about 3.30AM after a guest complained of noise.

'I checked but couldn’t find a pulse,' Niwano reportedly said, adding that the room was in a state of disarray. Bloodstains were later found on bed sheets and elsewhere. Niwano said when he asked the defendant what the victim’s name was, 'he said he didn’t know.'

Photographs taken in a bar a few hours before Furlong’s death reportedly show the two Irish women dressed in costumes and smiling. Statements from employees at the Scramble Cafe & Bar said Furlong fell unconscious about an hour after arriving there with Hinds and his friend James Blackston.

The court then watched CCTV footage showing the two Americans placing the unconscious women into a taxi on the way to their hotel, and discussing having sex with them. The second Irish woman was allegedly assaulted by Blackston in the back of the taxi while Furlong lay unconscious on the floor.

Footage taken inside an elevator shows the women in wheelchairs, with Furlong’s head lolling to one side. Niwano said he had supplied the wheelchairs because he thought the women had too much to drink. He had not suspected foul play.

The case continues and is expected to last to weeks, with the verdict due on March 19.