[Here is a little backstory about how Rey fell in love with Koda]
• Back in the days Kimball was actually Koda's first childhood friend but after she left Koda met Rey during their first year in elementary school. It was at this point that Rey developed a crush on Koda, it was at one point she promise to Koda that if stay together she would cook for him all day hinting at marriage but Koda wasn't aware that she was talking about marriage so he agreed. But after the destruction of the Waterthian planet and Koda's amnesia when the two do meet in the present day she is stricken with the news that Koda doesn't even remember her along with that promise. But not all is bad since now she can start over trying to win Koda's love and fulfilling that promise she made.
