The top-four companies according to the number of outlets (Yoshinoya Co., Ltd, Sukiya, Matsuya, and Nakau Company, Limited) may be called "Shitenno (four guardian kings)," because they keep far ahead of the others.
また、店舗数上位4社（吉野家、すき家、松屋、なか卯）が抜きん出ているため、『四天王』と呼ぶ場合もある。