A film I've been looking for for a very long time !
I’m looking for a live-action children's movie I saw on DVD sometime between 2010 and 2015. It features a Japanese or Korean boy, around 10 years old, who loves swimming. He meets a small, magical, beige creature—shaped like a seed or a potato—that helps him in his daily life and triggers magical events. During a school test, the creature sits in a tree outside the classroom window and whispers the answers to him after looking at the other students' papers. There is a scene in a movie theater where the boy enters the movie screen, thanks to the creature, and is chased by a T-Rex. Later, there is a scene where fish fly out of a pond to help him fish. Towards the end, the creature gets angry and grows to a massive size—about four or five meters tall—in a forest. Sorry im french btw 😅