  Recent observations in X-ray and Gamma-ray suggest that the emission region
of the pulsar magnetosphere can be multifold. In particular, the open-close
boundary of the magnetic field, so-called the Y-point, can be the new candidate
place where magnetic field energy converts into the plasma heat and/or flow
energy. Here, we present a new Particle-in-Cell code, which can be applied to
the Y-point of the pulsar magnetosphere in axisymmetric geometry. The
electromagnetic solver is used in the two-dimensional grid points with the
cylindrical coordinate (R, z), while the particle solver operates in the
three-dimensional Cartesian coordinate (x, y, z), where the Buneman-Boris
method is used. The particle motion is treated in special relativity. The inner
boundary conditions are set up to generate rotation of the magnetosphere by use
of the force-free semi-analytic solution given by Uzdensky (2003, ApJ, 598,
446).
  The code has been verified by dispersion relations of all the wave modes in
electron-positron plasmas.
  The initial test run is also presented to demonstrate the Y-shaped structure
at the top of the dead zone on the light cylinder. We suggest that the
structure is variable with quasi-periodicity associated with magnetic
reconnection and that plasma will be accelerated and/or heated. In a
time-averaged point of view, break up of the ideal-MHD condition takes place in
the vicinity of the Y-point.
