Women played a very important roll in the ninja clans of the past. Known as Kunoichi, the female ninja could often use their own femininity to get very close to the enemy.
Using psychological warfare and mind manipulation as weapons, the kunoichi could get in close enough to poison the victim without leaving a trace.
Kunoichi were trained in a variety of weapons, similar to the ninja, but because of the different situations they would face some smaller close range weapons were used more often.
Weapons like blinding powders, poisons, daggers, rope and even the fan were often carried because they could be used at close range and would be easy to transport without notice.
Imagine a young woman crying, and how it would make you feel. You'd probably want to try to help her, and maybe even offer her some assistance. This is just one example of how the kunoichi could trick someone into walking right into a trap, a very powerful weapon.
The clothing worn by the kunoichi depended on the situation, maybe it called for no clothes, who knows?
Women's History Magazine