  It has been a long-standing problem how the transverse M5-branes are
described in the matrix-model formulations of M-theory. We consider this
problem for M-theory on the maximally supersymmetric pp-wave geometry, which
admits transverse spherical M5-branes with zero light-cone energy. By using the
localization, we directly analyze the strong coupling region of the
corresponding matrix theory called the plane wave matrix model (PWMM). Under
the assumption that the low energy modes of the scalar fields in PWMM become
mutually commuting in the strong coupling region, we show that the eigenvalue
density of the $SO(6)$ scalars in the low energy region exactly agrees with the
shape of the spherical M5-branes in the decoupling limit. This result gives a
strong evidence that the transverse M5-branes are indeed contained in the
matrix theory and the theory realizes a second quantization of the M-theory.
