  We report the first statistical analyses of [CII] and dust continuum
observations in six strong OI absorber fields at the end of the reionization
epoch obtained by the Atacama Large Millimeter/Submillimeter Array (ALMA).
Combined with one [CII] emitter reported in Wu et al. (2021), we detect one
OI-associated [CII] emitter in six fields. At redshifts of OI-absorbers in
non-detection fields, no emitters are brighter than our detection limit within
impact parameters of 50 kpc and velocity offsets between $\pm200\ {\rm km\
s^{-1}}$. The averaged [CII]-detection upper limit is $< 0.06$ Jy ${\rm km\
s^{-1}}$ (3$\sigma$), corresponding to the [CII] luminosity of $L_{\rm [CII]}
<5.8\times 10^7\ L_{\odot}$ and the [CII]-based star formation rate of ${\rm
SFR_{\rm [CII]}} < 5.5$ $M_\odot$ yr$^{-1}$. Cosmological simulations suggest
that only $\sim10^{-2.5}$ [CII] emitters around [OI] absorbers have comparable
SFR to our detection limit. Although the detection in one out of six fields is
reported, an order of magnitude number excess of emitters obtained from our
ALMA observations supports that the contribution of massive galaxies that
caused the metal enrichment cannot be ignored. Further, we also found 14
tentative galaxy candidates with S/N of $\approx4.3$ at large impact parameters
($>50$ kpc) and having larger outflow velocities within $\pm 600$ km s$^{-1}$.
If these detections are confirmed in the future, then the mechanism of pushing
metals at larger distances with higher velocities needs to be further explored
from the theoretical side.
