Chronologically episode 12.  The school's cultural festival day has arrived.  Kyon decides to skip the premiere of the SOS Brigade's video (seen in episode 1) and enjoy the festival.  While sleeping though some live band performances, a new band gets on stage named ENOZ.  Surprisingly, Yuki is playing lead guitar and Haruhi is the lead singer.  They do a great job and everyone likes them.  Haruhi tells Kyon later that she and Yuki were just filling in for two of the band who couldn't perform.