Fabrication of dense and highly textured ceramics is significantly important for the improvement of their anisotropic properties by the templated grain growth (TGG) method. Monte Carlo simulation based on the Potts model was carried out through computation for the design of TGG processing, in which anisometric template particles are mixed with fine matrix particles and organic binder and aligned by tape casting before heat treatment. Thus, four initial parameters affecting the microstructure after sintering with isotropic grain growth were investigated; 1) mixing ratio of template/matrix particles, 2) size and 3) aspect ratio of the template particles, and 4) initial porosity (caused by the removal of binder). The fraction of oriented grains in the simulated microstructure was found to increase with increasing template/matrix mixing ratio and aspect ratio of template, and with decreasing template size and initial porosity. The residual porosity was shown to decrease with decreasing template/matrix mixing ratio and template size, and with decreasing initial porosity. The study suggests that computational design would give a guiding principle in terms of the initial preparation conditions for the ceramics having both a large fraction of oriented grains and low residual porosity.