She's best known as the pianist who had a rough moment at the regional piano competition preliminaries—visibly upset about Amamiya and on the verge of tears. That's when Kai stepped in and cheered her up, which honestly became a turning point. After that encouragement, she figured out what her own musical style actually was.
She's got a running joke of calling Kai "Wendy" because his hair reminds her of a pet dog. Speaking of which, she actually has a dog named Wendy herself, and you'll usually find her hanging out in the restroom with the dog—it's kind of her favorite spot.
Coming from a family of overachievers probably put some pressure on her. She has four successful siblings, and she was definitely trying to prove herself to them and her parents through her playing. Eventually she managed to pull it off.
Content compiled by AnimeList.moe from publicly available sources.