  A compact gas cloud G2 is predicted to reach the pericenter of its orbit
around the super massive black hole (SMBH) of our galaxy, Sagittarius A* (Sgr
A*). This event will give us a rare opportunity to observe the interaction
between SMBH and gas around it. We report the result of the fully
three-dimensional simulation of the evolution of G2 during the first pericenter
passage. The strong tidal force by the SMBH stretches the cloud along its
orbit, and compresses it strongly in the vertical direction, resulting in the
heating up and flaring up of the cloud. The bolometric luminosity will reach
the maximum of $\sim100 L_{\odot}$. This flare should be easily observed in the
near infrared.
