Life looked grim for Yu, a loggerhead turtle, when she washed up in a Japanese fishing net five years ago, her front flippers shredded after a brutal encounter with a shark.
Now keepers at an aquarium in the western Japanese city of Kobe are looking for a high-tech solution that will allow the 25-year-old turtle to swim normally again after years of labor and 27 models of prosthetic fins behind them without achieving their goal.
Yu, weighing 227 pounds and 32 inches long, first came to the attention of keepers at the Suma Aqualife Park in Kobe after she was rushed there from a port on the southern island of Shikoku in 2008.
"She was in a really bad way. More than half her fins were gone and she was bleeding, her body covered with shark bites," said Naoki Kamezaki, the park's director general.
After nursing the loggerhead - an endangered species - back to health, keepers enlisted the help of researchers and a local prosthetics-maker to get her swimming again.
Early versions of prosthetic flippers caused her pain or fell off quickly, and with money short, Kamezaki said he sometimes felt like packing it in.
"There have been times I wanted to give up and just fix her up the best we can and throw her back in," he told Reuters. "Then if luck's on her side she'll be fine, if not, she'll get eaten and that's just life. The way of nature, I suppose."
The latest version - made of rubber and fixed together with a material used in diving wetsuits - was unveiled on February 11 and proclaimed a success, with Yu swimming smoothly around her tank.
But on Friday, one flipper slipped out as soon as she hit the water, forcing keepers back to the laboratory again.
Though Kamezaki admits that it's unlikely Yu will ever live a normal turtle life, he still has hopes.
"My dream for her is that one day she can use her prosthetic fins to swim to the surface, walk about, and dig a proper hole to lay her eggs in," Kamezaki said.
"When her children hatch, well, I just feel that would make all the trauma in her life worthwhile."