Reference for the voice can be heard here!

Kaede is an optimistic hard worker. As a leader type with a firm character, she has a strong will and doesn't hesitate to take action; her notable character trait being her strong sense of belief in herself and others. Her main motivation for playing the piano is to see others smiling. Kaede has a kind personality that makes her think about others before herself. Because of this, she is unable to immediately suspect people, as demonstrated in the demo by her going as far as faking an alibi out of her trust for Makoto, with no rational basis for his innocence, even if she can be a little silly and oblivious at times.