In Episode 1, through scrolling message, she mentionned that she is looking for "her prince". Many hints, such as the Keppi-looking brushes holder in Episode 5, revealed that they're indeed the Kappa Prince and that the two of them already got close. It is finally confirmed in Episode 7 that they're dating.
Not just aware of but knowing the heir to the Kappa Kingdom, Sara helps Keppi though is prone to indirectly hindering him. One such instance included her sneezing only to gracefully kick the heir to the throne into a machine he was working on resulting in Keppi being frozen solid. She was powerless to prevent the frozen Keppi from sliding into the path of a lorry where he was smashed to pieces. With the know how on how to repair Keppi, she did only to stick him back together in the wrong places.
Although Kazuki’s younger brother watches her daily on TV and in his mind has a personal connection with her by way of texting, Sara was unaware of his existence until meeting him at a fan meet and greet event. After her manager pulled Kazuki’s hair piece off, she handed Haruka his brother's possessions that he dropped.
At the end of Episode 10, Haruka tells Sara about the dreams he had since Episode 3 (or before that), adding that he was scared on making the choices between love or desire. Sara looks at the sky, saying that people refuse to communicate their feelings to each other and to work together. As a result, the fate of the world will be decided by the connections between all of us, if they exist or not.
Sara's adopted fathers in the Reo and Mabu manga. The two policemen found her as a baby, on a plate. They tried to found her biological parents, but they ended adopting her in the end.
One night, Reo and Mabu have a nightmare about a grown-up Sara that erased their memories and left them for good.
In the anime, they don't have much interactions, but after Sara learned that her fathers were working for the Otter Empire, she still trusted them as she says in the scrolling message. But, in Episode 11, everything seems to be fine as they no longer work for the Otter, and they both crowned their daughter.
A middle aged man who acted as her manager. Not much is known of how they could have met.
Though everyone was convinced otherwise that Kazuki was the real Sara only the manager was able to tell otherwise and was only successful in showing others by ruining Kazuki’s cover of Sara.
In Episode 5, Toi must lured Sara to a place where he can imprisonned her. Unfortunetly for him, Sara is a Kappa that can shapeshift at will, and she used that to tease him. In the end, Toi, exausted, didn't manage to capture her.