  We report intensive monitoring of the activity variability in the H$\alpha$
line for 10 Sun-like stars using the 1.88-m reflector at Okayama Branch Office,
Subaru Telescope, during the last four years 2019-2022. Our aim was to
investigate features of the stellar magnetic activity behaviors. We correlated
the H$\alpha$ line variability of each star with the stellar activity levels
derived from the Ca II H&K line, suggesting its efficiency as a magnetic
activity indicator. In analyzing the H$\alpha$ line variation, we observed that
some stars exhibited linear or quadratic trends during the observation period.
Among several G- and K-type stars expected to have co-existing activity cycles,
we confirmed the 2.9-yr short cycle of $\epsilon$ Eri (K2V) from the H$\alpha$
observations. Additionally, we established upper limits on the H$\alpha$
variability of $\beta$ Com (G0V) and $\kappa$$^1$ Cet (G5V) concerning their
expected shorter cycles. We also detected the possibility of short-term
activity cycles in two F-type stars, $\beta$ Vir (F9V; $\sim$ 530 days) and
$\alpha$ CMi (F5IV-V; $\sim$ 130 days). The cycle in $\alpha$ CMi was observed
in only one season of our 4-yr observations, suggesting the temporal absence of
the cycle period. However, for stars with planets, we did not observe
significant magnetic activity variability likely associated with the planetary
orbital period. It is speculated that the impact of H$\alpha$ variability on
radial velocity (RV) measurements may vary with spectral type.
