From The Stargate Omnipedia

Japanese scientist stationed with the Atlantis expedition in the Pegasus Galaxy. It is likely that she has the Ancient gene naturally, and not as a result of Dr. Carson Beckett's gene therapy.

Dr. Kusanagi may be Miko.


The Gift - When Dr. Beckett's availability runs thin, McKay and Zelenka request the presence of Dr. Kusanagi to assist them with Atlantis's chair-weapons platform.
The Siege, Part 1 - Plugged into the Ancient chair, Dr. Beckett pleads to be relieved of the duty by offering up Dr. Kusanagi instead.