R. Dorothy Wayneright (R・ドロシー・ウェインライト, Āru Doroshī Weinraito) is Roger's assistant. Introduced in Act:01 as Dorothy Soldano, daughter of rich scientist Miguel Soldano, she is later revealed to be an android constructed by him. Her actual "father" would be Timothy Wayneright, the man who commissioned her construction and father of the real Dorothy Wayneright. To show her gratitude, and as a form of payment for Roger's help, she decides to move in with him and help out Norman with the chores.

A running gag of sorts is Dorothy's habit of playing the piano very early in the morning. This greatly annoys Roger, because she plays it in a noisy fashion, despite the fact that Dorothy is an adequate piano player.

Her design was based partially on that of the Megadeus, and as such she seems to have a special connection to gigantic beasts. She sympathizes with them at times, and can sense their thoughts and emotions through empathy and sometimes through what may be a form of telepathy. Such Megadueses like the Archetype and the Leviathan are drawn to her, and the Big Fau could not operate without her core memory.

Although Dorothy seems to lack the ability to exhibit emotion, she does indeed have them. She was very attached to Wayneright, whom she considered to be a father, and would often sing for him. She also shows much respect and a sense of companionship and understanding towards Norman. She is also capable of kindness and compassion, as is shown when she takes in a stray cat and treats it in a maternal fashion. She forms a strong friendship with a R. Instro, a fellow android and her piano teacher.

Her relationship with Roger is complex at times. She is often confused by his irrational behavior and quirky habits, but at other times she seems to excel in areas of social interaction where Roger is lacking, and finds his ignorance of how to deal with certain situations amusing. She often calls him a "louse" when he behaves in an inappropriate manner. Despite this, it becomes apparent that she grows quite attached to Roger, and would risk her life to save him. She also admires his quest for the truth and his protection of the innocent and concern for others. It is hinted several times in the series that she may be in love with him. This can, at times, cause friction between herself and Angel, Roger's other main love interest.

Source: Wikipedia