Previous Monte Carlo simulations have shown that ordered tetratic phases can emerge in a dense two-dimensional Brownian system of rotationally asymmetric hard kites having 90° internal angles.However,there have been no exper-imental investigations yet to compare with these simulation results.Here,we have fabricated two types of micron-sized kites having internal angles of 72°-90°-108°-90° and 72°-99°-90°-99°,respectively,and we have experimentally stud-ied their phase behavior in two-dimensional systems.Interestingly and in contrast to the Monte Carlo simulations,the experimental results show a phase sequence of isotropic fluid-hexagonal rotator crystal-square crystal as the area fraction φA increases for both types of kites.The observed square crystal displays not only a quasi-long-range translational order but also (quasi-)long-range 4-fold bond-and molecular-orientational order;these characteristics confirm that tetratic order can emerge even in dense Brownian systems of rotationally asymmetric particles.A model based on local polymorphic configurations (LPCs) is proposed to understand the origin of the square lattice order in these dense kite systems.The results in this study provide a new route to realize custom-designed self-assembly of colloids by controlling LPCs.