One of the Main characters of Ultimate Girls. She is called Ultimate Girl Kyonyu by the spectators because of her breast size.
Vivenne Otori is one of Silk's best friends along with Tsubomi. She has a secret crush on Silk. One day with Silk and Tsubomi they were going to watch a monster fight with UFO-man and were accidentally crushed by him. He resurrected them but they had to take his place in fighting the monsters that attack the country every week. Vivenne becomes nervous to the thought of indecent exposure too become Ultimate Girl and after effects, because her mother told her it's improper to be naked. She does not try her powers as an Ultimate Girl until Tsubomi fails in her first transformation and Silk refuses to do so again. Left no choice, she offers to go, being dubbed Ultimate Girl Kyonyu (Big Boobs) by spectators. When attempting to avoid exposing herself when her suit deteriorates, Vivienne discovers she is weak and is easily beaten by the monster. UFO-man then tells her and the others how their powers are supposed to work, by being embarrassed, they generate an energy which can be projected as a weapon against the giant monsters.
When Vivenne uses UFO-mans power she becomes Ultimate Girl Kyonyu and she wears a red costume. Vivenne is probably one of the strongest of the three, as she is able to handle the monsters better than Silk and Tsubomi. She is also skilled in hand to hand combat and knows many wrestling moves. She is also able to use the energy attack because she becomes easily embarrassed when her suit deteriorates.