The girl found out the boy stole the umbrella because she could see that it was missing. She saw that there was a trail of raindrops going up the stairs to the attic that the boy left behind when he took the umbrella. The trail led her to find the boy trying to hide the umbrella in the attic cupboard. The girl was aggressive towards the boy after she saw that he had stolen her umbrella. When he sees the umbrella, the little boy remembers the past when he was poor. He was living without a home with his dad who used to have a yellow umbrella. His dad left him at the children’s home. The boy tells the girl and her mother his story and they give him the yellow umbrella to keep. Later we see that when the boy is an old man he works in an umbrella store. He gives the yellow umbrella to a little girl. He thinks he sees his dad outside with the umbrella and chases after him but it is only a memory. He falls down and his wife, who is the little girl all grown up, helps him stand up. They walk back to the umbrella store and you can see in the sign that the umbrella shop belongs to them.