  We present the kinematic anaylsis of $246$ stars within $4^\prime$ from the
center of Orion Nebula Cluster (ONC), the closest massive star cluster with
active star formation across the full mass range, which provides valuable
insights in the the formation and evolution of star cluster on an
individual-star basis. High-precision radial velocities and surface
temperatures are retrieved from spectra acquired by the NIRSPEC instrument used
with adaptive optics (NIRSPAO) on the Keck II 10-m telescope. A
three-dimensional kinematic map is then constructed by combining with the
proper motions previously measured by the Hubble Space Telescope (HST)
ACS/WFPC2/WFC3IR and Keck II NIRC2. The measured root-mean-squared velocity
dispersion is $2.26\pm0.08~\mathrm{km}\,\mathrm{s}^{-1}$, significantly higher
than the virial equilibrium's requirement of
$1.73~\mathrm{km}\,\mathrm{s}^{-1}$, suggesting that the ONC core is
supervirial, consistent with previous findings. Energy equipartition is not
detected in the cluster. Most notably, the velocity of each star relative to
its neighbors is found to be negatively correlated with stellar mass. Low-mass
stars moving faster than their surrounding stars in a supervirial cluster
suggests that the initial masses of forming stars may be related to their
initial kinematic states. Additionally, a clockwise rotation preference is
detected. A weak sign of inverse mass segregation is also identified among
stars excluding the Trapezium stars, though it could be a sample bias. Finally,
this study reports the discovery of four new candidate spectroscopic binary
systems.
