  We have employed a magnetic field angle as a tuning parameter in a
comprehensive measurement of the specific heat, magnetocaloric effect, and
magnetization for the quasi-kagome Kondo lattice CeRhSn, which is considered to
exhibit zero-field quantum criticality driven by geometrical frustration. By
constructing the field-angle-resolved landscape of the entropy, we unexpectedly
revealed that the non-Fermi-liquid nature survives up to a metamagnetic
crossover field of roughly 3 T in the very narrow field-orientation range,
close to the direction parallel to the quasi-kagome plane. We propose that spin
fluctuations along the hexagonal $c$ axis are the dominant driving force for
the non-Fermi-liquid behavior because it is strongly suppressed by a
magnetic-field component along the $c$ axis. The multidimensional entropy
landscape, which directly reflects the degeneracy of ground states, opens a new
route for uncovering the nature of exotic phases in anisotropic systems.
