Arnis, also known as Eskrima and Kali, is a real-life fighting style that is used in the Tekken universe. It is the national sport and martial art of the Philippines. The three names for the art are roughly interchangable umbrella terms for the traditional martial arts of the Philippines ("Filipino Martial Arts," or FMA) that emphasize weapon-based fighting with sticks, knives, bladed weapons and various improvised weapons.
Eskrima is a style of combat that emphasizes on weapon-based combat that generally involves sticks and knives. An unarmed variant of the style focuses much more on reacting to and countering an attack rather than offensive striking. However, viscious strikes and kicks are still used.