The most tender beef on the steer comes from the tenderloins, two small cylindrical muscles in the middle of the steer’s back that do very little work. Tenderloin steaks (aka filet mignons) are rich, buttery-soft pillows of beefy goodness, and Kobe filet mignons are even more so.
Wagyu beef (commonly known as "kobe beef" aka kobe-style beef or Australian kobe beef) is from a breed of cattle descended from Japanese herds, specially raised to increase its percentage of fat marbling to consistently high levels. More marbling leads to more flavor, tenderness, and moisture as the fat melts during the cooking process. Thus, wagyu filet mignons are both more flavorful and more tender than those cut from conventional beef.