  The Twin Higgs scenario stabilizes the Higgs mass through an approximate
global symmetry and has remained natural in the face of increasingly stringent
LHC bounds on colored top partners. Two basic structural questions in this
framework concern the nature of the twin hypercharge gauge symmetry and the
origin of the $\mathbb{Z}_2$ symmetry breaking needed to achieve the correct
vacuum alignment. Both questions are addressed in a simple extension of the
Mirror Twin Higgs model with an exact $\mathbb{Z}_2$ symmetry and a scalar
field that spontaneously breaks both twin hypercharge and $\mathbb{Z}_2$. Due
to the $\mathbb{Z}_2$ symmetry and an approximate $U(2)$ symmetry in the
potential, a new hypercharge scalar appears in the visible sector and, like the
Higgs, is a pseudo-Nambu-Goldstone boson with a weak-scale mass. Couplings
between the hypercharge scalar and matter provide a new dynamical source of
twin sector fermion masses. Depending on the nature and size of these
couplings, a variety of experimental signatures may arise, including quark and
lepton flavor violation, neutrino masses and mixings as well as direct collider
probes of the hypercharged scalar. These signals are correlated with the twin
matter spectrum, which can differ dramatically from the visible one, including
dynamical realizations of fraternal-like scenarios.
