The inter-dimensional system of a three-dimensional bulk and a two-dimensional interface is analyzed for bosons with quasirelativistic dispersion relation. Using the energy-dependent Green's function, the inter-dimensional quasirelativistic density of states inside the interface is solved analytically. We find that in the low-energy limit the inter-dimensional quasirelativistic density of states shows three-dimensional behaviour, while in the high-energy limit the density of states shows two-dimensional behaviour. This work is the first step in a process that will lead to a fully-analytical model for fermions in topological materials.