The first look with the penguin tail coat is her first design and was going to be the only design until the request for a brother was asked by a user from deviantart named "humaloidsforlife". He asked for a brother who cross dresses like Riku, so then her second design was born and so was her brother Kawasaki Oni. Her brother is also a cross dresser so to pair up the two of them just use the boy version of Riku with the female version of Oni and vice versa. She does have a voice bank but the person who made her also is a HUMAloid as well, the creator says that because she "has no life" so she chooses to be a HUMAloid. Eve thought the tom boy Riku is out the creator usually uses the girl Riku because there are more girl songs then boys.
Some information about Riku:
When she was created she was 16 now she is 17.
She is 160 lbs
Likes:Nice people, to play dress up, friends, people who are different, berries, and melon
Dislikes:Mean people, nasty people, people who are homophobic, those who are ignorant, her D size breasts.
Personality: A nice person, calm, quiet, usually likes to be alone, only smiles near people she cares about, very mean only to people who are mean to her cared ones very tomboyish, when singing she has little emotion for the song and doesn't care about much. Very outgoing and bright, usually called a nerd by her sister Meru and called 'missle boobs' by her brother, because of her 'weirdness of being a humaloid' she is usually taunted by other UTAUloids.
Please note that the person who made Riku Kawasaki goes by the name VISA and is known around Nicodouga as VISA-p. For youtubers and Niconicodouga people please take into consideration that Riku and VISA are both Humaloids.