Ritsuko Akagi is NERV's head scientist. The daughter of Naoko Akagi, the developer of the MAGI supercomputers, she is a lonely, cool and intelligent woman who has great affinity for cats and is completely devoted to her work. In flashbacks, it is revealed that she was one of Misato's first friends following the Second Impact. Ritsuko was also friendly with Kaji, and jokingly flirted with him, which is often misinterpreted by fans as evidence of a past romance.
Source from Wikipeida