  We consider mesons composed of light and heavy quarks and discuss the
construction of the corresponding meson wave functions in soft-wall AdS/QCD. We
specifically take care that constraints imposed by chiral symmetry breaking and
by the heavy quark limit are fulfilled. The main results are: i) the wave
functions of light mesons have a nontrivial dependence on the current quark
mass, which gives rise to a mass spectrum consistent with the one including
explicit breaking of chiral symmetry; ii) the wave functions of heavy-light
mesons generate their correct mass spectrum, the mass splittings of vector and
pseudoscalar states, and the correct scaling of leptonic decay constants f(Q
\bar q) \sim 1/sqrt(mQ); iii) the wave functions of heavy quarkonia produce
their correct mass spectrum and lead to a scaling behaviour of the leptonic
decay constants f(Q \bar Q) \sim sqrt(mQ) and f(c \bar b) \sim mc/sqrt(mb) at
mc << mb, consistent with potential models and QCD sum rules.
