  We extend the holographic duality between 3d pure gravity and the 2d Ising
CFT proposed in [Phys. Rev. D 85 (2012) 024032] to CFTs with boundaries.
Besides the usual asymptotic boundary, the dual bulk spacetime now has a real
cutoff, on which live branes with finite tension, giving Neumann boundary
condition on the metric tensor. The strongly coupled bulk theory requires that
we dress the well-known semiclassical AdS/BCFT answer with boundary gravitons,
turning the partition function into the form of Virasoro characters. Using this
duality, we relate the brane tensions to the modular S-matrix elements of the
dual BCFT and derive the transformation between gravitational solutions with
different brane tensions under modular S action.
