In recent years, there has been a development in approaching rationality problems through motivic methods. This approach requires the explicit construction of degeneration families over curves with favorable properties. However, the specific construction is generally difficult. Nicase and Ottem focused on tropical compactification and constructed degeneration families of hypersurfaces in toric varieties from finite-dimensional linear systems on algebraic tori. As an application, they discussed the rationality of hypersurfaces in projective space. In this talk, I will attempt to generalize this research and present the following two points. First, I will introduce the notion of mock toric varieties, which are generalizations of toric varieties. Second, I will combinatorially construct degeneration families of hypersurfaces in mock toric varieties, and I will mention the irrationality of a very general hypersurface in the complex Grassmannian variety Gr(2, n).