  We investigated the nature of the anomalies appearing in four microlensing
events KMT-2020-BLG-0757, KMT-2022-BLG-0732, KMT-2022-BLG-1787, and
KMT-2022-BLG-1852. The light curves of these events commonly exhibit initial
bumps followed by subsequent troughs that extend across a substantial portion
of the light curves. We performed thorough modeling of the anomalies to
elucidate their characteristics. Despite their prolonged durations, which
differ from the usual brief anomalies observed in typical planetary events, our
analysis revealed that each anomaly in these events originated from a planetary
companion located within the Einstein ring of the primary star. It was found
that the initial bump arouse when the source star crossed one of the planetary
caustics, while the subsequent trough feature occurred as the source traversed
the region of minor image perturbations lying between the pair of planetary
caustics. The estimated masses of the host and planet, their mass ratios, and
the distance to the discovered planetary systems are $(M_{\rm host}/M_\odot,
M_{\rm planet}/M_{\rm J}, q/10^{-3}, \dl/{\rm kpc}) = (0.58^{+0.33}_{-0.30},
10.71^{+6.17}_{-5.61}, 17.61\pm 2.25,6.67^{+0.93}_{-1.30})$ for
KMT-2020-BLG-0757, $(0.53^{+0.31}_{-0.31}, 1.12^{+0.65}_{-0.65}, 2.01 \pm 0.07,
6.66^{+1.19}_{-1.84})$ for KMT-2022-BLG-0732, $(0.42^{+0.32}_{-0.23},
6.64^{+4.98}_{-3.64}, 15.07\pm 0.86, 7.55^{+0.89}_{-1.30})$ for
KMT-2022-BLG-1787, and $(0.32^{+0.34}_{-0.19}, 4.98^{+5.42}_{-2.94}, 8.74\pm
0.49, 6.27^{+0.90}_{-1.15})$ for KMT-2022-BLG-1852. These parameters indicate
that all the planets are giants with masses exceeding the mass of Jupiter in
our solar system and the hosts are low-mass stars with masses substantially
less massive than the Sun.
