Xu bu 虚步 the Empty Stance is also known at a Cat Stance in most Japanese martial arts. It is called an Empty Stance because the front leg is mostly empty of weight. It is used for retreat, absorbing, evading an attack. Because the front leg does not have much weight, it can also be used for setting up for a kick.
The weight distribution is about 90-10. The only weight that is in the front foot is the weight of the leg. The back leg holds the weight of the upper body.