This research numerically explores the feasibility of a one-way flow between two finite-sized planar plates, each with a different uniform temperature. In the case of infinite plates, a periodic distribution of the accommodation coefficient enables a one-way flow. An actual plate inevitably has its edges, and in the rarefied gas, the edge in a non-uniform temperature field induces localized fast flow—thermal edge flow. The present results show that the one-way flow by the distribution of the accommodation coefficient is also possible for finite-sized plates as well as infinite plates. The one-way flow survives under strong thermal edge flow vortices. We also report the optimal aspect ratio between the plate spacing and the period length of the distribution that maximizes the one-way flow as a function of the Knudsen number.