  We present continuum and molecular line (CO, C$^{18}$O, HCO$^+$) observations
carried out with the Atacama Large Millimeter/submillimeter Array toward the
"water fountain" star IRAS 15103-5754, an object that could be the youngest PN
known. We detect two continuum sources, separated by $0.39\pm 0.03$ arcsec. The
emission from the brighter source seems to arise mainly from ionized gas, thus
confirming the PN nature of the object. The molecular line emission is
dominated by a circumstellar torus with a diameter of $\simeq 0.6$ arcsec (2000
au) and expanding at $\simeq 23$ km s$^{-1}$. We see at least two gas outflows.
The highest-velocity outflow (deprojected velocities up to 250 km s$^{-1}$),
traced by the CO lines, shows a biconical morphology, whose axis is misaligned
$\simeq 14^\circ$ with respect to the symmetry axis of the torus, and with a
different central velocity (by $\simeq 8$ km s$^{-1}$). An additional
high-density outflow (traced by HCO$^+$) is oriented nearly perpendicular to
the torus. We speculate that IRAS 15103-5754 was a triple stellar system that
went through a common envelope phase, and one of the components was ejected in
this process. A subsequent low-collimation wind from the remaining binary
stripped out gas from the torus, creating the conical outflow. The high
velocity of the outflow suggests that the momentum transfer from the wind was
extremely efficient, or that we are witnessing a very energetic mass-loss
event.
