This story encourages readers to make predictions. Imagination and play are essential ingredients that invite children to read, and at the same time they can write their first stories orally.

Emilia, the main character, has picked up something in the school garden and does not allow anyone to discover what the mysterious thing is that she keeps in her backpack. In fact, it is an unlikely friend: a hippopotamus with whom the girl strikes up an intimate friendship, like any child with his first pet.