|This article contains information that only comes from the anime, not the manga.|
For more information on this, see Filler Episodes.
Rina has light brown hair that is tied into a bun. She also wears bangs. On her yellow shirt with a red round border is a green pattern that resembles a four-leaf clover. Rina is still wearing light blue shorts.
Rina thought her own father was a liar and hated him for it. She could also never quite come to terms with the fact that he had left her and never came back. She never really believed in the gem like that and believed that her father had lied to her again. In a flashback, her father told Sayo that Rina couldn’t forgive so easily once she was angry. Remembering her father’s words that anything can come true if you believe in it, she abruptly changed her mind about his research.
Three years ago, their father told them that he had found a way to solve all the problems in the village, because he liked it very much. That was where Rina and Sayo’s mother was born. The said way was to make a gemstone, however, his daughters did not quite believe in it. Soon after, he moved out of the village and the two sisters had to fend for themselves from then on. They were still laughed at by the villagers, but they learned to cope. A month ago of the current events, Nuki was standing at the front door with the notebook. He had the notebook and a letter with him, saying that Rina and Sayo should complete his research.
When Sayo and Rina ran into the Straw Hats on Spa Island, they were treated to a meal by them. Shortly after, however, Foxy and his cronies Hamburger and Porche showed up. Using a mirror device, they were able to incapacitate Rina, her sister, and several members of the Straw Hat Pirates thanks to Foxy’s Slow Beam. The latter then took her father’s notebook from Sayo. However, after thirty seconds, they were able to move normally again and Luffy hurled the trio away with the Gomu Gomu no Bazooka. In the process, Foxy dropped the notebook and Sayo took it back.
Nami thought it was strange and asked what the notebook was all about. Rina persuaded Sayo to tell the secret. This would be that her father had made a note in the book about making a gemstone. Shortly after, Rina told the straw hats about her past. However, Sayo suddenly fell through a trapdoor, and a Den-den Mushi through which Doran spoke challenged them to solve the riddle of the gem if they wanted to see Sayo again. After most of the island was destroyed by the Straw Hat Pirates, the chimney suddenly became a cannon pointed at Sayo.
Doran now wanted the notebook, but Sayo forbade her sister from giving it to him. When Luffy destroyed Spa Island with Gear 3, he fell into the water in his small form along with Rina and Nuki. There, Rina discovered an underwater volcano at the bottom of the ocean that looked like a large X, the same symbol that was in the notebook. Through this, a circular rainbow was eventually created, also called the “Gem of the Sea”, which meant it was her father’s treasure. They managed to make the gemstone. They mixed seven chemicals and arranged them in the colors of the rainbow, thus succeeding in doing so.