  A kinematic misalignment of the stellar and gas components is a phenomenon
observed in a significant fraction of galaxies. However, the underlying
physical mechanisms are not well understood. A commonly proposed scenario for
the formation of a misaligned component requires any pre-existing gas disc to
be removed, via fly-bys or ejective feedback from an active galactic nucleus.
In this Letter, we study the evolution of a Milky Way mass galaxy in the
FIREbox cosmological volume that displays a thin, counter-rotating gas disc
with respect to its stellar component at low redshift. In contrast to scenarios
involving gas ejection, we find that pre-existing gas is mainly removed via the
conversion into stars in a central starburst, triggered by a merging satellite
galaxy. The newly-accreted, counter-rotating gas eventually settles into a
kinematically misaligned disc. About 4.4 (8 out of 182) of FIREbox galaxies
with stellar masses larger than 5e9 Msun at z=0 exhibit gas-star kinematic
misalignment. In all cases, we identify central starburst-driven depletion as
the main reason for the removal of the pre-existing co-rotating gas component,
with no need for feedback from, e.g., a central active black hole. However,
during the starburst, the gas is funneled towards the central regions, likely
enhancing black hole activity. By comparing the fraction of misaligned discs
between FIREbox and other simulations and observations, we conclude that this
channel might have a non-negligible role in inducing kinematic misalignment in
galaxies.
