The invention provides non-spherical resin particles with a novel shape capable of improving light diffusion, adhesion, oil absorption, and other properties, as well as a manufacturing method and use of the particles. Each non-spherical resin particle includes a concave portion and a convex portion formed in the concave portion, wherein the convex portion has a quasi-spherical surface. The method of manufacturing non-spherical resin particles involves a step of polymerizing 100 parts by weight of a first monomer mixture containing 77 to 99.99 parts by weight of a branched alkyl methacrylate, 0.01 to 3 parts by weight of a polyfunctional monomer, and 0 to 20 parts by weight of a monofunctional (meth)acrylate which is not a branched alkyl methacrylate, in the presence of 0.1 to 0.9 parts by weight of a chain transfer agent and 0 to 100 parts by weight of a (meth)acrylate polymer, to obtain resin particles.