Both Big Dog, and Small dog are doing nothing. Well, the big one is chewing a can; and when his partner, accidentally hits him, it goes away bouncing, and ends up in Y-MART.
It seemed easy to go after a can. And that's what they did, they went down the street, to the store. And Small Dog took the can, so he could give it back to "its owner". But, since Big Dog doesn't seem to understand when the small one has the can in his mouth, this one throws it away, and gets to the "other side": inside the store- when a person walks in, and the door automatically opens.
So, Small Dog decides to use shoes, like people do. So he can open the door, too. He steals a kid's, and also firemen's boots. Even Cinderella's, and a baseball player. They go to one of those "private clubs", and ask the girl to take her shoe off. With a lot of shoes, ready to put on the floor outside the store's door, he puts all of those there. But doesn't seem to work; he thought it was because he had to wear them, but that didn't work either! Big Dog sits on that floor, and the door finally opens.
They're inside, at last. But they forgot what they were inside for. They cause a mess, which makes all the people around run. Even the firemen pass by them. And then... the automatic door closed. They were now trapped inside.