1Q84 Book 1: April - June by Haruki Murakami

The number of people who could deliver a kick to the balls with Aomame's mastery must have been few indeed. She had studied kick patterns with great diligence and never missed her daily practice. In kicking the balls, the most important thing was never to hesitate. One had to deliver a lightning attack to the adversary's weakest point and do so mercilessly and with the utmost ferocity-just as when Hitler easily brought down France by striking at the weak point of the Maginot Line. One must not hesitate. A moment of indecision could be fatal.

Generally speaking, there was no other way for a woman to take down a bigger, stronger man one-on-one. This was Aomame's unshakable belief. That part of the body was the weakest point attached to-or, rather, hanging from-the creature known as man, and most of the time, it was not effectively defended. Not to take advantage of that fact was out of the question.