  We determine the kinetic coefficients of ultrasoft pions using chiral
perturbation theory at finite temperature close to the chiral limit. This is
used to compute the axial charge diffusion and damping coefficients in the
hydrodynamic effective theory for these pion waves. We show that to provide a
leading order answer for these coefficients one needs to explore the dynamics
of hard, soft, and ultrasoft pion modes, which are represented microscopically
by the appropriate kinetic and hydrodynamic descriptions..
