  We investigate information flow and Page curves for tripartite systems. We
prepare a tripartite system (say, A, B, and C) of a given number of states and
calculate information and entropy contents by assuming random states.
Initially, every particle was in A (this means a black hole), and as time goes
on, particles move to either B (means Hawking radiation) or C (means a broadly
defined remnant, including a non-local transport of information, the last
burst, an interior large volume, or a bubble universe, etc.). If the final
number of states of the remnant is smaller than that of Hawking radiation, then
information will be stored by both of the radiation and the mutual information
between the radiation and the remnant, while the remnant itself does not
contain information. On the other hand, if the final number of states of the
remnant is greater than that of Hawking radiation, then the radiation contains
negligible information, while the remnant and the mutual information between
the radiation and the remnant contain information. Unless the number of states
of the remnant is large enough compared to the entropy of the black hole,
Hawking radiation must contain information; and we meet the menace of black
hole complementarity again. Therefore, this contrasts the tension between
various assumptions and candidates of the resolution of the information loss
problem.
