Big Brozu is the twenty-first episode of the first season of Kappa Mikey.
Gonard is holding Mitsuki captive in a room on the side of a building. Gonard threatens Mitsuki with his laser sword. Just then, Team LilyMu flies alongside the building in Gonard's helicopter. Mikey fires at the robots in the room with a laser. Mitsuki manages to free herself and run to the window. Gonard shoots Mitsuki in the leg with his laser before she jumps from the window. Mitsuki falls short of the helicopter. Mikey sends the helicopter into a nosedive in order to rescue her, but almost crashes it. Guano ends the scene.
Ozu arrives and berates Mikey for his reckless actions, but is cut short by the arrival of un unknown person. The man is revealed to be Ozu's twin Brother, Brozu. Brozu's antics impress Mikey but annoy Ozu and the rest of the cast. Ozu tells Brozu to leave, but Brozu refuses, revealing that he owns fifty-one percent of LilyMu, due to being born one second earlier than Ozu. Ozu cites an agreement between the two of them allowing Ozu to run LilyMu, but Brozu resolves to stay. Ozu is forced to let Brozu stay and make whatever changes he wants.
The cast complain about Brozu, but Mikey still speaks highly of him. The cast discover that Brozu has added fog machines, club lights, and a disco ball to the LilyMu set, angering Ozu. Mikey vouches for Brozu, but Ozu shuts him down. Brozu speaks to Mikey privately, turning him against Ozu.
Mikey and Brozu arrive in Ozu's office, where Ozu had been waiting with the rest of the cast for them to arrive for a meeting. Brozu announces that he is firing Ozu and replacing him with Mikey. Ozu departs, with Mikey denying involvement in the decision. Guano suggests that Mikey apologize to Ozu, but Brozu whisks Mikey away to take his place as the new producer. Mikey is quickly enamored with the perks of his new position.
Ozu confronts Brozu and suggests that they build Brozu his own dance club for him to run, a prospect which he prefers over running LilyMu.
The cast go to Mikey to complain about how he is running the show. Mikey annoys them with his behavior and they leave. Mikey then discovers that he must do a large amount of paperwork as part of his new job. Mikey asks Brozu if he or Ozu could run the show, but Brozu rejects these ideas. He tells Mikey that his contract ensures that he will be producer for the foreseeable future. Mikey resolves to do his job poorly in an attempt to be removed from his position.
Ozu discovers that Brozu has built his dance club on the roof of LilyMu Towers, directly above Ozu's penthouse. Ozu goes to Brozu to complain, but Brozu ignores him.
Mikey makes several changes to the script, hoping they will prompt Brozu to remove him as director. The cast refuse to act out the nonsensical script Mikey has created. Angry at him, they resolve to go on strike.
The cast hold a strike in front of the studio. Mikey goes to them to apologize and explain his intentions. They eventually forgive him, and the cast attempt to come up with a plan to get Ozu back. They go to speak with Ozu, who is still mad at Mikey for taking his job. Mikey apologizes and the cast ask Ozu to become the producer of a new show with them in it. Ozu refuses, stating that he cannot bring himself to abandon LilyMu.
The cast meet in Mikey's office to plan their next move. They make a discovery in Mikey's contract that they think will help them.
The cast confront Brozu in his dance club. Mikey cites a clause in his contract allowing him to challenge Brozu for ownership of LilyMu. Brozu accepts Mikey's challenge, declaring that they will compete in a dance-off. The competition begins, and Brozu quickly demonstrates himself to be the better dancer. Suddenly, Ozu arrives and coaches Mikey through an impressive dance routine, allowing him to win the dance-off. Ozu regains control of LilyMu and closes the dance club, forcing Brozu out.
The LilyMu episode is finished, with Team LilyMu breaking through the window and defeating Gonard with the power of dance.