On a bright and sunny day, the little mouse Jerry opens his door and takes a deep breath of the fresh morning air. Soon, he discovers a new friend in the yard—a cheerful and adorable little seal. This little fellow has escaped from a circus, tired of the monotonous and repetitive performances. He shows Jerry all his tricks, and the two quickly become inseparable friends. To help the seal, Jerry sneaks into the house and steals the breakfast fish belonging to the old cat Tom. Of course, Tom won’t sit idly by while his food is taken by someone else, so he angrily chases after Jerry. By chance, Tom hears a radio broadcast announcing a reward for capturing the little seal. Tempted by the money, Tom shifts his target to the little seal beside Jerry. To protect his new friend, Jerry bravely throws himself into the fray. A chaotic chase unfolds in the yard.