Velocity-resolved [O III]λ5007 channel maps in TN J0121+1320 illustrate the kinematic evolution of the ionized gas across the emission-line profile. In the most blueshifted slices (λ < 0.5000 μm), the emission is concentrated in two compact knots separated by ∼1″ (∼7.5 kpc). These features likely trace high-velocity, blueshifted gas near the AGN. As the slices approach the systemic wavelength, [O III] emission exhibits an extended, asymmetric structure, bridging the two knots and revealing they are part of a coherent ionized structure coincident with the radio AGN location. When the slices go progressively redder, a third emission component ∼2″ east of the radio AGN core becomes prominent at these velocities. This feature, which was completely absent in the blue wings, may reflect lower velocity gas or a distinct companion system as suggested by W. Wang et al. (2025a).