  Given their prominent role in galaxy evolution, it is of paramount importance
to unveil galaxy interactions and merger events and to investigate the
underlying mechanisms. The use of high-resolution data makes it easier to
identify merging systems, but it can still be challenging when the morphology
does not show any clear galaxy-pair or gas bridge. Characterising the origin of
puzzling kinematic features can help to reveal complicated systems. Here, we
present a merging galaxy, MaNGA 1-114955, in which we highlighted the
superimposition of two distinct rotating discs along the line of sight. These
counter-rotating objects both lie on the star-forming main sequence but display
perturbed stellar velocity dispersions. The main galaxy presents off-centred
star formation as well as off-centred high-metallicity regions supporting the
scenario of recent starbursts, while the secondary galaxy hosts a central
starburst which coincides with an extended radio emission, in excess with
respect to star formation expectations. Stellar mass as well as dynamical mass
estimates agree towards a mass ratio within the visible radius of 9:1 for these
interacting galaxies. We suggest we are observing a pre-coalescence stage of a
merger. The primary galaxy has accreted gas through a past first pericentre
passage about 1 Gyr ago, and more recently from the secondary gas-rich galaxy,
which exhibits an underlying active galactic nucleus (AGN). Our results
demonstrate how a galaxy can hide another one and the relevance of a
multi-component approach to study ambiguous systems. We anticipate our method
to be efficient at unveiling the mechanisms taking place in a sub-sample of
galaxies observed by the Mapping Nearby Galaxies at Apache Point Observatory
(MaNGA) survey, all exhibiting kinematic features of puzzling origin in their
gas emission lines.
