Its starts off with Paddington and Mr. Gruber leaving a train station in Japan. Mr. Gruber brings Paddington to Japan to help with reasearch for his book. They are visiting a rikishi which is a training school for sumos. They meet the teacher and the teacher takes Paddington's suitcase thinking he was staying. Paddington gave the dissaproval face which was taught to him by his Aunt Lucy. The teacher wants him to teach the class the face but Paddington refuses. The teacher sends Paddington off to the back with the rest of the young sumos.
The teacher and Paddington go to the class while they are doing a sand excercise which he says builds upper body strength, and lower body balance. The teacher offers Paddington if he would like to try and he agrees. Paddington is so good at it that he makes a mound taller than himself.
Then they go to another room for dojo training. The teacher explains the rules and the biggest student who is lifting Paddington in the picture enters the ring. All the other sumos where defeated then it was Paddingtons turn. Then the lunch bell rang and they went to eat.
They have an eating contest where they started with 4 bowls. The biggest student eats 7 then stops. Paddington eats roughly around 21 and he's still hungry. Then they go to the sleeping area for a nap. Paddington couldn't sleep so he went into the hall to pretend to fight a statue. The other students join him. Then the biggest announces it was time for the tournament. They entered the arena and it was the biggest student vs. Paddington again. The bigger charged Paddington and Paddington hung on to his stomach while the bigger sumo stepped out. The result was that Paddington had beat him. Then they lift Paddington in the air to celebrate.