In weak stratification, the horizontal component of the Earthʼs rotation vector Ω cosφ (φ and Ω represent the latitude and angular velocity, respectively) plays a crucial role in the behavior of near-inertial waves. In the limit for N ＝0, such as the Bottom Water in the abyssal Japan Sea, the momentum equations yield a solution for a pure inertio wave (also called Gyroscopic Wave: GsW). However, there is little observational evidence to support the existence of GsW. In this study, we theoretically show an asymmetric ray path from the GsW dispersion relation along with a weak stratification. Additionally, it is demonstrated that when southward propagating near-inertial GsW reflects on the sea bottom, it enables an irreversible transformation of a vertical low-wavenumber to a vertical high-wavenumber. Interestingly, the rotation of the horizontal current ellipse (horizon tal projection of true current ellipse) for the incident wave changes transiently from clockwise to anti-clockwise although the reflected wave rotates truly clockwise. Based on this knowledge and the reproduction experiment for GsW using a numerical model, the evidence suggesting a reflection of GsW could be found in the current data of the mooring system installed near the sea bottom.