  We present high-cadence photometric and spectroscopic observations of
supernova (SN) 2024ggi, a Type II SN with flash spectroscopy features which
exploded in the nearby galaxy NGC 3621 at $\sim$7 Mpc. The light-curve
evolution over the first 30 hours can be fit by two power law indices with a
break after 22 hours, rising from $M_V \approx -12.95$ mag at +0.66 days to
$M_V \approx -17.91$ mag after 7 days. In addition, the densely sampled color
curve shows a strong blueward evolution over the first few days and then
behaves as a normal SN II with a redward evolution as the ejecta cool. Such
deviations could be due to interaction with circumstellar material (CSM). Early
high- and low-resolution spectra clearly show high-ionization flash features
from the first spectrum to +3.42 days after the explosion. From the
high-resolution spectra, we calculate the CSM velocity to be 37
$\pm~4~\mathrm{km\,s^{-1}} $. We also see the line strength evolve rapidly from
1.22 to 1.49 days in the earliest high-resolution spectra. Comparison of the
low-resolution spectra with CMFGEN models suggests that the pre-explosion
mass-loss rate of SN 2024ggi falls in a range of $10^{-3}$ to $10^{-2}$
M$_{\odot}$ yr$^{-1}$, which is similar to that derived for SN 2023ixf.
However, the rapid temporal evolution of the narrow lines in the spectra of SN
2024ggi ($R_\mathrm{CSM} \sim 2.7 \times 10^{14} \mathrm{cm}$) could indicate a
smaller spatial extent of the CSM than in SN 2023ixf ($R_\mathrm{CSM} \sim 5.4
\times 10^{14} \mathrm{cm}$) which in turn implies lower total CSM mass for SN
2024ggi.
