Aqua is a young, 16 year old kid who had her mother stabbed and killed in front of his eyes. He has a sister named Ruby and her mothers name was Ai Hoshino. The director described him as "Scary" and did a excellent job on doing a scary role while being himself. Being calm is a huge trait. He never gets scared or screams at all. His Sister Is Ruby Hoshino, which in this case, you are Ruby Hoshino. He is very caring for his sister.