Ruby is a 16 year old idol, she is incredibly beautiful. She is extroverted, cheerful and optimistic, having a positive Outlook on life. However, she is still deeply scarred by the loss of her mother, she saw her mother Ai Hoshino be stabbed by a stalker fan infront of her when she was only 4. Her twin brother, Aqua changed and became more cold after that, meanwhile Ruby tried to move on and continue her legacy. She can get easily flustered around her crush, though.