  We investigate the collective plasmon modes in double layer of two
dimensional materials where either one or both of the layers have tilted Dirac
cone. Consistent with quite generic hydrodynamic treatment, similar to double
layer graphene systems we find two branches of plasmons. The in-phase
oscillations of the two layers disperses as $\sqrt q$, while the out-of-phase
mode disperses as $q$. When even one of the layers hosts tilted Dirac cone
spectrum, the plasmonic kink which is a salient feature of a monolayer of
tilted Dirac cone is inherited by both of these branches. In double layers
composed of graphene (nontilted) and borophene (tilted) where the two layers
have two different Fermi velocities, the velocity scale of plasmonic modes is
set by the greater of the two. The kink always takes place when each plasmon
mode crosses an energy scale $\omega_{\rm kink}$. When the two layers have
different chemical potentials, there will be two such scales, and each of
in-phase and out-of-phase modes develop two kinks. Moreover we find that an
additional linearly dispersing overdamped mode of monolayer tilted Dirac cone
system survives in the double layer system.
