  In the past two decades, one of the most puzzling phenomena discovered in
hadron physics is that a nominal hadronic state can actually correspond to two
poles on the complex energy plane. This phenomenon was first noticed for the
$\Lambda(1405)$, then for $K_1(1270)$, and to a lesser extent for
$D_0^*(2300)$. In this Letter, we show explicitly how the two-pole structures
emerge from the underlying universal chiral dynamics describing the
coupled-channel interactions between heavy matter particles and pseudo
Nambu-Goldstone bosons. In particular, the fact that two poles appear in
between the two dominant coupled channels can be attributed to the particular
form of the leading order chiral potentials of the Weinberg-Tomozawa form.
Their lineshapes overlap with each other because the degeneracy of the two
coupled channels is only broken by explicit chiral symmetry breaking of higher
order. We predict that for light-quark~(pion) masses heavier than their
physical values (e.g., about 200 MeV in the $\Lambda(1405)$ case studied), the
lower pole becomes a virtual state, which can be easily verified by future
lattice QCD simulations. Furthermore, we anticipate similar two-pole structures
in other systems, such as the isopin $1/2$ $\bar{K}\Sigma_c-\pi\Xi'_c$ coupled
channel, which await for experimental discoveries.
