  Recently, Naruse presented a beautiful cancellation-free hook-length formula
for skew shapes. The formula involves a sum over objects called excited
diagrams, and the term corresponding to each excited diagram has hook lengths
in the denominator, like the classical hook-length formula due to Frame,
Robinson and Thrall. In this paper, we present a simple bijection that proves
an equivalent recursive version of Naruse's result, in the same way that the
celebrated hook-walk proof due to Green, Nijenhuis and Wilf gives a bijective
(or probabilistic) proof of the hook-length formula for ordinary shapes. In
particular, we also give a new bijective proof of the classical hook-length
formula, quite different from the known proofs.
