Io

A young DearS who appears to Takeya on the roof of his school in volume 6 of the manga. She can only say one word: "Ren". It is later revealed that she is the mysterious "Sample A2" that China was sent to retrieve. It is also revealed that her ability to manipulate gravity is phenomenally powerful — strong enough to levitate Takeya's entire apartment building. She may also possess the ability of teleportation. She eventually matures into the second DearS Watcher, and decided to take her people in search of a new host populace. (from Wikipedia)