Motoko Kusanagi often just addressed as The Major is the main protagonist of the Ghost in the Shell, anime, manga and movies. Major Kusanagi is the head of the assault team of the Japanese task force titled Section 9, which patrols for and works against acts of cyber-terrorism.
At around age six Motoko needed to convert into a full prosthetic body with only her brain and part of her spinal cord remaining organic, the rest of her body was entirely artificial and she spent years getting accustomed to using it, upgrading from one model to another as she aged. Motoko became a gifted hacker and was eventually recruited into the police force Public Security 9, an anti-cyber terrorism task force. In conjunction with her need to become cybernetically savvy due to her fully prosthetic body at a young age and her interest in cyber-brain technology Kusanagi was further trained in high-end technology for the task-force and is one of the nation's most brilliant hackers and certainly the most brilliant one on government pay roll in Japan. Kusanagi is the Major of Section 9 second in command to chief, Daisuke Aramaki, the official overseer of the entire project. Aramaki rarely gives orders directly, instead trusting the Major with most local oversight and at her own request field-work. The Major is talented enough to hack even active cyber-brains and uses her skill to directly access the memories of suspects, information from prisoners and on occasion even hijacks the bodies of criminals to undermine their own group's crimes. Her current prosthetic body is highly modified from it's original model settings to be more useful for covert espionage and with Kusanagi's highly sophisticated, yet completely biological, brain at the helm she is essentially hack proof.
Her greatest antagonist is The Puppetmaster. Her relationship with him will have long-lasting consequences for him and for her in ways that are still to be seen.
For the most part the Major is a no nonsense cop. Technically all field work such as spying, breaking and entering and the purchase of black market goods are illegal but all such activities are expected of Section 9 and covered up due to an understanding with the Prime Ministry. Also though the Major may occasionally circumvent normal police procedure to spare those that might normally become victimized by the system by in large, she is dedicated to her job and safe guarding the public. She is also very stoic and seems to be fazed by almost nothing; Batou even notes this once, asking if there's anything she's afraid of.
Despite her seemingly cold attitude, the Major is far from heartless. She considers her fellow officers not just partners but friends and is good friends with Chief Aramaki and Batou in particular.