  This talk presented the first muon anti-neutrino disappearance analysis using
data from the T2K anti-neutrino data taken in 2014 and up to March 12, 2015.
The preliminary measured oscillation parameters, using $2.3\times 10^{20}$
protons on target, are $\Delta \bar{\rm{m}}_{32}^{2} = 2.33_{-0.23}^{+0.27}
\times 10^{-3}~$eV$^{2}$, and sin$^{2} \bar{\theta}_{23} =
0.515_{-0.095}^{+0.085}$. These oscillation parameters are consistent with the
neutrino mode, and with the measurements of the MINOS experiment.
