They planned to meet again at 9:40 p.m. that night.
But it was after 10 p.m., and her sister wasn't there.
It wasn't until a detective approached her on the beach that Denise Fujimoto learned her sister had been hit by a motorboat and fatally injured.
She never heard her sister scream, and had no idea there had been an accident.
Skyler Shepherd the owner of the boat who is on trial in connection with the accident told police he left the woman and motored away because he was unaware she had been hurt.
Shepherd told a Weber County Sheriff's detective during a taped interview played for the jury on Thursday that he could only see the injured swimmer from the chest up, and didn't see any injuries.
"The lady spoke to me. She was angry with me. 'Help' never left her mouth while I was there," Shepherd told the detective.
Fujimoto, however, had been horribly and fatally injured by the motor boat's propeller.
Shepherd, 22, is charged with misdemeanor counts of reckless endangerment, obstructing justice and failure to render aid.
Closing arguments and jury deliberation are slated for Friday morning.
Two of Shepherd's friends, Colton Raines, 23, and Robert Cole Boyer, 30, are charged with obstructing justice. And Raines, who was driving the boat when Fujimoto was hit, also is charged with reckless endangerment and failure to render aid. Trials for Raines and Boyer are set for February.
In the video interview, Shepherd appears alongside his attorney, Glen Neeley, and he explains that he was on his boat with Raines and Boyer when Raines said he wanted to take the boat out for one last run before sunset. As Raines was driving near Spring Creek, he saw a swimmer wearing black and swerved to miss her.
Shepherd said Raines stepped back from the driving wheel and put his hands up, indicating that he didn't want to drive any longer.
"[Raines] says, 'I can't drive the boat,'" Shepherd told the detective. "He's just like freaking out."
So Shepherd said he took over, turned the boat around and went to check on the swimmer.
He asked the woman twice if she was OK, he told the detective.
The swimmer responded with "Yeah," and a loud grunt, he said.
"[She was] just mad," Shepherd told the detective. "Just like pissed off. I thought to myself, well sh, if someone came close to me, I'd be pissed, too."
Shepherd said that he thought Fujimoto was all right and that his friend had managed to miss the swimmer.
But earlier this week, Chief Medical Examiner Todd Grey testified that Fujimoto likely would have known she was injured. She suffered severe injuries to her lower abdomen and legs, her femoral artery was cut and she was bleeding to death, Grey testified.
After Shepherd spoke with police, detectives took a patrol boat to Pineview Reservoir in an effort to reenact the accident, and determine if the three men really could not see into the water or hear the woman's screams, as Shepherd claimed.
Weber County Sheriff's detective Scottie Sorensen testified on Thursday that he could clearly hear the screams of the man who was in the water during the reenactment, despite the fact that the patrol boat's motor is much louder than Shepherd's. He also said he could clearly see the swimmer in the water.
"I could see down into the water," he said. "I could see his legs. I could see his midsection, torso, and his arms, of course."
Neeley took issue with reenactment, saying that many differences, including the fact that the swimmer wasn't wearing a black wetsuit and it was not windy that day, could discredit the accuracy of the exercise.
Fujimoto was not in a no-wake zone when she was struck, Sorensen said. But the area is popular with open water swimmers, and is generally not frequented by boats because the water is very shallow, and most boaters would not want to risk getting stuck, according to Sorensen. However, at the time of the accident, the reservoir was especially high that year because of a heavy snow runoff from the mountains.
Sorensen said the area did not prohibit swimmers, nor did it prohibit boaters, though he said boats were not commonplace in the area.
"It would be abnormal for boats to have been [there,]" he said.
Two women who were boating with Shepherd on that day testified that they spent much of their day wakeboarding or with the boat tied down at "Party Cove," where they drank whipped cream-flavored vodka and spiced rum on Shepherd's boat. And they said several people on the boat but not Shepherd smoked marijuana that day.
Both women said Shepherd appeared agitated or upset when they left the marina, which was closed for about two hours after the accident.
According to court documents, the boaters were questioned by wildlife officials later that day but did not disclose they were involved in an accident. The men also allegedly wiped down the boat before it could be examined by police. Neeley said in his opening statement that Shepherd did not talk to wildlife officials because he didn't know for sure if there was an accident, and they were initially told officials were looking for a blue boat; his was white and green.
After the state rested their case on Thursday, Neeley called one witness Suzanne Miles, a forensic scientist with the Utah State Crime Lab who testified that no DNA evidence was found on Shepherd's boat.
Shepherd waived his right to testify.
Framed photos of Fujimoto a 49-year-old University of Utah medical researcher were passed around among family members and friends before the trial began Thursday morning. Her brother, Andy Fujimoto, said the photos helped them to remember the person that Fujimoto was.
"[They helped] to remember my sister not as a trial. Not as a piece of evidence, but as a person," he said Thursday.