Jonathan, a ten-year-old boy from a suburb of Barcelona, spends his afternoons listening to the adventures of Sponge Man, a superhero created by the Boss, his summer camp instructor.
| Actor | Role |
|---|---|
 Zoe BerriatúaJefe | Jefe |
 Graciela MolinaSocorro Soriano | Socorro Soriano |
| CCarlos RajaJonathan | Jonathan |
| CChristian GuerraJuanmi | Juanmi |
| JJosu BarónAlbert | Albert |
| AAgustín GarabitoLuis | Luis |
| ÁÁlex RosiñoPau | Pau |
| JJoaquín BoñaMarc | Marc |
 Jordi SánchezJordi | Jordi |
| OOriol GonzálezGaming Console Kid | Gaming Console Kid |
| RRosario ÁguilaJonathan's Mother | Jonathan's Mother |
| AAritz LekuonaEl Hombre Esponja | El Hombre Esponja |
 Andrés GertrúdixOlder Jonathan (voice) | Older Jonathan (voice) |