Katie Ledecky, Caeleb Dressel and the other storylines to watch as Olympic swimming begins

Katie Ledecky is the defending Olympic champion in the 200-, 400- and 800-meter freestyle -- and the favorite to win the 1,500-meter free, which is debuting in Tokyo. Tom Pennington/Getty Images

Arguably the greatest women's swimmers of all time, Katie Ledecky will look to build on her legacy as she takes aim at four individual golds in Tokyo. Caeleb Dressel will attempt to live up to the hype as the "new Michael Phelps." And Ryan Murphy will try to create history as the first American to win two back-to-back gold medals in the 200-meter backstroke.

In short, the U.S. team has a storyline for every occasion as the swimming competition begins on Saturday at the Summer Olympics. Here are five to follow in Tokyo.

Ledecky's dominance

Phelps explained it best at the U.S. Olympic swim trials in Omaha, Nebraska -- there is no other swimmer who has been able to pick a style and successfully swim the entire spectrum of it.

"She is recreating what is possible," Phelps said. "That is awesome to watch."

In Tokyo, five-time gold medalist Ledecky will race in the 200-, 400-, 800- and, for the first time in Olympic history, the 1,500-meter freestyle races. And guess what? She is favored to medal in all of the events, including gold in the 800- and 1,500-meters.

At the Olympic trials, Ledecky, 24, won all four events, finishing so far ahead of the field in the 800 and 1,500 meters that no one else was visible on the screen, qualifying for her third Olympics.

In 2016, before the 1,500-meter freestyle was a part of the Olympics, Ledecky won gold in the other freestyle competitions. Will she be able to pull off a repeat performance plus a gold in the 1,500 meters? If she does, she will become the first Olympian to win gold in all four events.

Can Simone Manuel win a gold in another event?

Simone Manuel, 24, became the first Black woman to win an individual medal in swimming in 2016, when she won the 100-meter freestyle at the Rio Olympics. In Tokyo, however, she won't be swimming in her marquee event.

At the Olympic trials, Manuel finished ninth in the semifinals of the 100-meter freestyle, missing the final cut by 0.02 seconds. At a news conference later, she revealed that she had been diagnosed with overtraining syndrome (OTS) about two months before, suffered from depression and had to take a three-week break from swimming.

Two days later, on the last day of trials, she surprised again by winning the 50 meters, securing a spot in Tokyo.

At training camp earlier this month, when asked how she is preparing for the Olympics with her OTS diagnosis, Manuel said that she was taking care of herself and taking breaks as much as needed.

Dressel's Tokyo run could bring back memories of Phelps' performances at the Beijing Olympics

Dressel could win seven gold medals at the Tokyo Olympics.

Allow that sentence to sink in. If not for Phelps' record of eight Olympic golds in Beijing, that projection might be completely off base. But the forecast could have merit since Dressel won every single heat he competed in at the Olympic trials: 50-meter freestyle, 100-meter freestyle and 100-meter butterfly.

Every single one of them.

Based on his career trajectory since his record-breaking performance at the world championships in 2019, when he won eight medals, including six golds, it's safe to say that Dressel could evoke the same superstar feelings in fans as Phelps did in Beijing.

Maybe Dressel can't equal Phelps' record, but he could come darn close.

Katie Grimes, the breakout star at swim trials, is the 'future of the sport'

If there was one clear rookie standout at the Olympic trials, it was 15-year-old Katie Grimes, who in the 800-meter freestyle, finished five seconds behind Ledecky to earn an Olympic berth. In the process, Grimes also achieved her personal best time (8:20.36, shaving off 12 seconds from her previous best) and edged out veteran distance swimmer Haley Anderson.

What's more: Ledecky was in the exact same spot as Grimes in 2011 at her first Olympic trials, also at age 15. She finished second in the 800-meter freestyle, to make her first Olympics.

Recently, Ledecky introduced Grimes to a news conference as the "future of the sport," while Grimes looked around, dazed and happy.

Will Murphy keep America's long-lasting backstroke record alive?

With all the major storylines swimming around ahead of Tokyo, you might have missed this one: Americans have won gold in both the 100- and 200-meter backstroke in every Olympics since 1992 -- before Murphy was born.

At the 2016 Olympics, which was Murphy's first, he followed tradition and won both events, stamping Team USA's dominance.

Will he be able to achieve a repeat performance to keep the record alive? Only two Americans have ever won the 100-meter backstroke at back-to-back Olympics (Aaron Peirsol in 2004 and 2008 and Warren Kealoha in 1920 and 1924).

If Murphy, 26, wins a gold in the 200-meter backstroke, he will become the first American to win that race at back-to-back Olympics.