Distribution of planets in the plane of the host, M_h, and planet, M_p, masses for planetary systems with known masses. Planetary systems with host masses at around or below the stellar mass limit are denoted by colored points: a red dot for KMT-2018-BLG-0748L, blue triangle dots for the other microlensing planetary systems, and green square dots for the seven planets in TRAPPIST-1 system. The yellow shaded area represents the region with mass ratios q = M_p ∕M_h ≥ 0.1. The dashedvertical line represents the star/BD boundary. The dotted horizontal lines represent the masses of the Jupiter, Saturn, Uranus, Earth, and Mars of the solar system from the top to bottom.