Os Under-Undergrounds

"The Under-Undergrounds" (Portuguese: Os Under-Undergrounds) is a Brazilian animated musical comedy children animated television created by Hugo Oda for Nickelodeon and premiered in May 9th, 2016.
The second season debuted in February 6th, 2021.
Plot.
The story tells the story of Heitor, a teen guitarist who is kicked out of his band because they think he is not cool enough. On his way home, upset about the happening, he falls in a hole and ends up in an underground world, inhabited by mutant creatures. Although it is in this weird place that he is going to find everything he was looking for: true friends and a rock'n'roll band that doesn't care about stereotypes, only the passion for music. The Under-Undergrounds, together, will have lots of fun adventures trying to help Hector find his way back home. Tolerance, diversity, companionship and self-knowledge are values that our "Rock Star hero" will learn in order to be respected and loved by the "Undergrounders".