  Detecting $\rm H_I$ 21cm line in the intergalactic medium (IGM) during the
Epoch of Reionization (EoR) suffers from foreground contamination such as
Galactic synchrotron and extragalactic radio sources. Cross-correlation between
the 21cm line and Lyman-$\alpha$ emitter (LAE) galaxies is a powerful tool to
identify the 21cm signal since the 21cm line emission has correlation with LAEs
while the LAEs are statistically independent of the foregrounds. So far, the
detectability of 21cm-LAE cross-power spectrum has been investigated with
simple LAE models where the observed Ly$\alpha$ luminosity is proportional to
the dark matter halo mass. However, the previous models were inconsistent with
the latest observational data of LAEs obtained with Subaru/Hyper Suprime-Cam
(HSC). Here, we revisit the detectability of 21cm-LAE cross-power spectrum
adopting a state-of-the-art LAE model consistent with all Subaru/HSC
observations such as the Ly$\alpha$ luminosity function, LAE angular
auto-correlation, and the LAE fractions in the continuum selected galaxies. We
find that resultant cross-power spectrum with the updated LAE model is reduced
at small scales ($k\sim 1\ \rm Mpc^{-1}$) compared to the simple models, while
the amplitudes at large scales ($k \lesssim 0.2 \ \rm Mpc^{-1}$) are not
affected so much. We conclude that the large-scale signal would be detectable
with Square Kilometre Array (SKA) and HSC LAE cross-correlation but detecting
the small scale signal would require an extended HSC LAE survey with an area of
$\sim 75\ \rm deg^2$ or 3000 hrs observation time of 21cm line with SKA.
