Characteristics of two-dimensional metamaterials based on non-orthogonal grids of transmission lines are investigated. From periodic analysis on a unit cell, the dispersion function is derived and compared with the orthogonal grid case. Isomorphism between Kirchhoff's circuital laws and two-dimensional Maxwell's equations is utilized to characterize the effective medium parameters. It is shown that a non-orthogonal grid structure is effective in realizing two-dimensional full-tensor anisotropic medium parameters in a simple geometrical configuration. For verification, a design example is provided where a probe current radiates near a planar interface between two anisotropic media and the results are compared with the analytical solution.