  We study gas and metal outflow from massive galaxies in protocluster regions
at $z=3-9$ by using the results of the FOREVER22 simulation project. Our
simulations contain massive haloes with $M_{\rm h} \gtrsim 10^{13}~\rm
M_{\odot}$, showing high star formation rates of $> 100~\rm M_{\odot}~yr^{-1}$
and hosting supermassive black holes with $M_{\rm BH} \gtrsim 10^{8}~\rm
M_{\odot}$. We show that the mass loading factor ($\eta_{\rm M}$) sensitively
depends on the halo mass and it is $\eta_{\rm M} = 1.2~(9.2)$ for $M_{\rm h} =
10^{13}~(10^{11})~\rm M_{\odot}$. Once the halo mass exceeds $\sim
10^{12.5}~\rm M_{\odot}$, the outflow velocity of the gas rapidly decreases
near a virial radius, and the gas returns to a galactic centre finally as a
fountain flow. Also, the metal inflow and outflow rates sensitively depend on
the halo mass and redshift. At $z=3$, the inflow rate becomes larger than the
outflow one if $M_{\rm h} \gtrsim 10^{13.0}~\rm M_{\odot}$. Thus, we suggest
that massive haloes cannot be efficient metal enrichment sources beyond virial
radii that will be probed in future observations, e.g., studies of metal
absorption lines with the Prime Focus Spectrograph on the Subaru telescope.
