Ruko Kurihara
About
Kurihara Ruko is a friend of Momoka and Sayaka. She is often asked by her friends to help them with their troubles; however, her words of advice can be quite merciless. She can read the quality of men by their "scent." She deeply cares about her friends and always checks out the boyfriends that Sayaka gets.
She can easily see that Shiratama is not a natural "Queen bee" but instead influenced to act as one by people around her.