Fuuka moves back to Tokyo from Osaka when Sana and Hayama start junior high school. When she and Sana meet (in the school bathroom, of course), they realize they're very similar in both looks and personality, and I have to agree to some degree.
Fuuka is very honest and possesses a strong will and a good heart. Like Sana, she tends to get hyper when she's angry, worried, or excited, but Fuuka is definitely calmer and more serious than Sana. She is also a very good student and great at gymnastics, which means she's very driven and dedicated.
While Fuuka has a good heart, she's a lot less innocent and soft-hearted than Sana, so sometimes she seems a bit colder. I think that's because Fuuka isn't as prone to thinking with her heart alone, and she considers how her actions will affect her. But Fuuka is a very good person and she takes good care of her friends.
Fuuka was the girl Hayama kissed on a bet when they were in kindergarten (because "one should experience all kinds of things when young" or some such bit of Hayama wisdom -_-;). That kiss caused Fuuka a lot of trouble with her crush, Takaishi-kun, so she was understandably very angry with Hayama for a long time. However, when she later meets Hayama again in junior high and gets to know him, she realizes she's very drawn to his personality.
I actually thought I wouldn't like Fuuka when I first found out about her existence, but it'd be hard not to like someone as genuine as her.
