  Strong gravitational magnification by massive galaxy clusters enable us to
detect faint background sources, resolve their detailed internal structures,
and in the most extreme cases identify and study individual stars in distant
galaxies. Highly magnified individual stars allow for a wide range of
applications, including studies of stellar populations in distant galaxies and
constraining small-scale dark matter structures. However, these applications
have been hampered by the small number of events observed, as typically one or
a few stars are identified from each distant galaxy. Here, we report the
discovery of 46 significant microlensed stars in a single strongly-lensed
high-redshift galaxy behind the Abell 370 cluster at redshift of 0.725 when the
Universe was half of its current age (dubbed the ``Dragon arc''), based on two
observations separated by one year with the James Webb Space Telescope ({\it
JWST}). These events are mostly found near the expected lensing critical
curves, suggesting that these are magnified individual stars that appear as
transients from intracluster stellar microlenses. Through multi-wavelength
photometry and colors, we constrain stellar types and find that many of them
are consistent with red giants/supergiants magnified by factors of thousands.
This finding reveals an unprecedented high occurrence of microlensing events in
the Dragon arc, and proves that {\it JWST}'s time-domain observations open up
the possibility of conducting statistical studies of high-redshift stars and
subgalactic scale perturbations in the lensing dark matter field.
