  We present a chemodynamical study of the Triangulum-Andromeda overdensity
(TriAnd) employing a sample of 31 candidate stars observed with the GRACES
high-resolution ($R$=40,000) spectrograph at the Gemini North (8.1 m)
telescope. TriAnd is a stellar substructure found toward the outer disk of the
Milky Way, located at $R_{\rm GC}\sim 18$ kpc from the Sun, toward Galactic
latitude $b \sim 25${\deg}. Most stars in our sample have dynamical properties
compatible with a disk stellar population. In addition, by applying an
eccentricity cut, we are able to detect a stellar contamination that seems to
be consistent with an accreted population. In chemical abundance space, the
majority of our TriAnd candidates are similar to the outer thin-disk
population, suggesting that the overdensity has an \textit{in situ} origin.
Finally, the found accreted halo interlopers spatially overlapping with TriAnd
should explain the historical discussion of the overdensity's nature due to its
complex chemical patterns.
