But, Sakuya isn't hyper. She is, perhaps, one of the most cool-headed characters in the story. She does love having fun, but I do not think that counts as being hyper.
Anyway, this was all that had to be posted as a reason why Sakuya would be anyone's favourite character:
Seriously, I cannot see Athena, Hina or Maria being able to look half as good as Sakuya does in that pic.