Young Daniel, who lives with his dog Anselmo, first meets Don Joaquín—an elderly concert pianist who has become a grumpy recluse. Daniel believes the two could be great companions, never suspecting that the man is actually his grandfather. Later, he meets Alejandra, and together they begin to explore new, fun-filled worlds—all thanks to the grandfather, who becomes their guide and teaches them the true meaning of friendship and how to hold onto their childhood.