  The T2K neutrino oscillation experiment will start in 2009. In this
experiment the center of the neutrino beam from J-PARC at Tokai village will go
through underground beneath Super-Kamiokande, reach the sea level east of
Korean shore, and an off-axis beam at $0.5^{\circ}$ to $1.0^{\circ}$ can be
observed in Korea. We study physics impacts of putting a 100 kt-level Water
\cerenkov detector in Korea during the T2K experimental period. For a
combination of the $3^{\circ}$ off-axis beam at SK with baseline length L = 295
km and the $0.5^{\circ}$ off-axis beam in the east coast of Korea at L = 1000
km, we find that the neutrino mass hierarchy (the sign of $m^2_{3} - m^2_1$)
can be resolved and the CP phase of the MNS unitary matrix can be constrained
uniquely at 3-$\sigma$ level when \sin^2 2\theta_{\rm rct} $ \ge 0.06 $.
