Sumo Of All Fears is the twelfth episode of the first season of Kappa Mikey.
Gonard is dangling Lily and a buss full of people off of a bridge. The rest of Team LilyMu arrive to save them. Gonard releases the bus and Lily, forcing Mikey to choose which one he will rescue. Mikey swoops in and grabs both Lily and the bus, but cannot support the bus's weight and drops it. Guano ends the scene.
Mikey complains about being forced to lift the bus's weight, but it is revealed that the bus is merely a prop that the rest of the cast can lift effortlessly. Mikey finds that he is not strong enough to lift the bus and declares that he will exercise in order to become stronger.
Mikey goes to the gym with Guano to lift weights. There, he notices a group of sumo wrestlers and decides to ask them how to become strong.
Lily and Mitsuki are playing tennis against each other. Gonard is practicing with a tennis ball machine and is struck repeatedly with tennis balls, including one from Lily. Lily and Mitsuki find Gonard, seemingly assaulted, and offer to take care of him.
Mikey accidentally slips and falls into one of the sumo wrestlers. The wrestlers interpret this as a challenge and force Mikey to fight the wrestler, who is the yokozuna. Mikey is given one hour to prepare for the fight. The gym's janitor offers to train Mikey to fight. The janitor has Mikey mop the floor, claiming it is part of his training.
Lily and Mitsuki have taken Gonard back to their apartment, where they tend to him. Gonard feigns trauma in order to get Lily and Mitsuki to care for him.
The janitor has Mikey and Guano perform a variety of janitorial tasks, saying that they are part of his training. Eventually, the hour is up, and Mikey is forced to fight the yokozuna. The battle begins, but Mikey discovers that the janitor was lying to him and that the "training" accomplished nothing. Mikey is easily overpowered by the yokozuna.
Lily and Mitsuki realize that Gonard is merely pretending to be injured and come up with a plan to get rid of him.
Mikey manages to defeat the yokozuna by tickling him. Mikey is declared the new yokozuna, the strongest man in Japan. The other sumo wrestlers begin to challenge Mikey for the title of yokozuna. Mikey and Guano flee from the challengers.
Lily and Mitsuki bring Yoshi, disguised as a doctor, to their apartment to check up on Gonard. The "doctor" diagnoses Gonard with a variety of ailments and forces him to wear full-body gauze, to Gonard's dismay.
Mikey and Guano attempt to hide from the challengers. Guano suggests that Mikey lose a fight in order to pass the title of yokozuna to somebody else, but Mikey is too afraid to do so. Suddenly, Mikey's new title is announces on television, prompting a wave of new challengers to appear. Mikey is called by Ozu, who tells Mikey that he must strengthen his mind or risk becoming his own worst enemy. Mikey comes up with a plan to solve his dilemma.
Threatened with intense medical treatment, Gonard abandons his act and admits that he is not really injured. Mikey arrives and asks Gonard to help him deal with the sumo wrestlers.
The LilyMu cast return to the gym, where Mikey seemingly accepts a challenge from a trio of masked wrestlers. In reality, the challengers are just Mikey, Gonard, and Guano in disguise. The sumo wrestlers accept the fake challenge and force them to fight themselves in a cage match. The three stage a mock battle, changing outfits to put on the appearance that they are actually fighting other people. Eventually, the "challengers" are able to defeat Mikey and his friends. They are declared the new yokozuna, but quickly remove their disguises, claiming that the new yokozuna have run away. The sumo wrestlers run off in search of the yokozuna. Back at LilyMu Studio, Ozu congratulates the cast on pulling off the plan.
The LilyMu episode is finished, with Mikey rescuing Lily and the rest of the team rescuing the bus and defeating Gonard.
- The title of this episode references the novel The Sum of All Fears and its film adaptation.
- This episode references the film Spider-Man.
- In real life, "yokozuna" is the highest ranking that a sumo wrestler can achieve.
- This episode references the film The Karate Kid.
- This episode references the song "Macarena".
- Mikey references the myth that the moon is made of cheese.
- This episode references the "sleeper hold", a professional wrestling move.