Understanding the sub-nanoscale solvation structures of ionic liquids is crucial for the development of innovative functional "devices" across numerous fields. We previously demonstrated the atomic-scale solvation measurements using an ultralow noise 3D frequency-modulation atomic force microscopy combined with molecular dynamics simulations. However, to facilitate practical applications, the molecular distribution on a heterosurface must be verified. Here, we unveil the local solvation structures on a heterogeneously charged phyllosilicate surface in an ionic liquid solution and pure liquid. By identifying adsorbed ion species from the molecular sizes and orientations, we experimentally demonstrate that anions and cations preferentially adsorbed onto the positive and negative surfaces exhibit different orientations and water miscibility. Moreover, we reveal that neutral intermediate regions are formed at the boundary region in ionic liquid media as well as a KCl solution. In the future, this technique will be essential for the evolution of ionic-liquid functional "devices".