X - HEART is an animated sitcom about three guys that are struggling to be worldwide rockstars. Alex and Sidnei met each other in internet and decided to start a rock band. They need a bass player to join the band, Sidnei invites his friend Zé. Zé doesn't know how to play bass but he accepts the invitation because he thinks it can be funny. Alex needs to pay rent, so he starts to work in a snack bar attended by rock bands.