Hero's Son and Rival's Nephew

Hero's Son and Rival's Nephew is an upcoming 2018 American animated buddy comedy drama film starring Mickey Mouse and directed by Brad Bird. The film will be released in theaters on June 22, 2018 produced by Walt Disney Animation Studios and distributed by Walt Disney Studios Motion Pictures.

Plot
Elmer Mouse is a young boy mouse who once lived alone in a tree house in the city of Mouseton. On the last day of school before summer vacation, Elmer had a nice daydream while on morning break, about him and the girl of his dreams, Maia Pfeffer. After the dream is finished, Elmer's two friends, Marius Kentis and Artie Holden come to tell him that their school's worst bully, Walter Cunningham is up to something wrong. They spy on Walter as he hijack the auditorium stage near the end of Principal Chesney's speech, creating his own fiery speech where Walter rails against the benefits and honors that students are entitled to, but Elmer, Marius and Artie stop him with the help of Chesney. The rally fails in making Walter a popular schoolmate and impressing his ex-girlfriend, Maia Pfeffer; and as result, he is sent to Chesney's office. Maia thanks Elmer for saving the auditorium and agrees to get together with him the coming evening. Eventually, Elmer, Marius and Walter are called in to the office, where they explain the occurrence and Chesney forewarns Walter's uncle, Mortimer Mouse that Walter's actions may result in him facing serious consequences, angering Mortimer.

After school, the students takes separate sides of the main entrance so that Elmer can come out of the front door, to be cheered on by his fellow classmates, but before he can leave, he is given thanks by his teacher, Herr Schmidt, Secretary Lerkel and Principal Chesney for making their last day of the school year. Elmer exits the school, running through the line between the two crowds, and Maia meets him at the beach for their get-together, but Walter has plans of revenge on Elmer for getting him in trouble.

Elmer sees Walter creep up behind them after he shoots his painted bald eagle figurine, smashing it to kingdom come and gets Maia to go into hiding while he tries to fend Walter off, resulting in a serious argument between the two and Maia, who takes Elmer's side despite Walter's objections, which angers him, prompting him to break apart Elmer's beach spot and run, hurting his feelings. That evening, Minnie Mouse finds a sad and alone Elmer on the beach. Following her advice to be himself and not fight back with people like Walter, Minnie takes the boy to her boyfriend Mickey Mouse's home, where they start getting to know each other well. That night, Mickey allows Elmer to stay with him in his home. Meanwhile, Mortimer and Walter have a heated argument on Maia and his stunt at school, resulting in Walter telling him he should get a girl, and Mortimer knows who, his ex-girlfriend, Minnie.

The next morning, Mickey is about to take Minnie out for a ride in his fancy car, a blue Ford Model A, and invites Elmer to come along with them. The three go to several locations that satisfy them. They stop at a cafe for a bite to eat where they meet Marius, Artie and their quirky friend, Dunbar Shoemeyer again. When Mickey's arch-enemy Pete overhears a conversation between Elmer and Mickey, he tells Mortimer, Walter and Walter's incompetent gang, the Kovacs, that Elmer has no parents and his mother is apparently dead. That afternoon, Mickey, Minnie and Elmer come to a cemetery, where Elmer leads them to his mother's grave. He tells them about his last memory of his mother, how he first met Mickey and how his mother died, which makes Minnie cry. The sad mice hold a moment of silence for Elmer's mother, until Pete, Mortimer and Walter sneak up behind them. As Walter openly insults Elmer in front of Mickey and Minnie because his mother his dead, and Mortimer tries to steal Minnie in front of Mickey, Elmer, his friends and the Kovacs, Mickey reaches a phone booth to call the police as Pete pulls out his Colt 45 gun to kill the boys, but Elmer rams headfirst into Walter, Mortimer and Pete and falls unconscious from the impact. Pete, Mortimer and Walter are arrested and sent to jail by Police Chief O'Hara while the paramedics come to take Elmer away, much to his friends' sadness.

Days later, Elmer recovers in the hospital from a concussion that he suffered from ramming into the three imprisoned criminals, and is released with a discharge and reunites with his friends, who waited outside. Elmer bids goodbye to his friends, promising to see them again sometime in the next few days or so, they accept and admit he has always been a good friend in school and the bravest before they leave for home. Elmer goes to Maia's home to visit her, which overjoys Maia, who is told by him his grief over his mother, but she understands and tells him he has a good father figure who will take care of him. Mickey and Minnie also learn that Elmer is safe and are overjoyed to see him alive and well. Mickey accepts Elmer as an adoptive son, and he happily to introduces them as well as his fancy rat Bobo to Maia.

Cast

 * Bret Iwan as Mickey Mouse, the hero and the beloved citizen of Mouseton.
 * John Sturtridge as Elmer Mouse, a young boy mouse who becomes Mickey's friend and later adopted son.
 * Russi Taylor as Minnie Mouse, Mickey's ever-loving girlfriend who understands Elmer and brought him to Mickey to raise.
 * Gavin MacIntosh as Walter Cunningham, a pre-teenage mouse who wants Maia, who does not like him. The conflict makes him Elmer's sworn enemy.
 * Bill Farmer as Pluto, Mickey's beloved pet dog.
 * Kaitlyn Maher as Maia Pfeffer, a girl mouse who was in love with Elmer since their first day they met in Mouseton.
 * Maurice LaMarche as Mortimer Mouse, Walter's uncle and Mickey's longtime rival who is constantly after Minnie's affections and hurting Elmer on the street.
 * Zach Hammer as Marius Kentis, an older friend of Elmer's who is allowed to drive.
 * Dakota Fanning as Elisabeth Cronkite, Marius' girlfriend, who taught him how to drive safely, which helped.
 * Davey Towers as Artie Holden, a smart friend of Marius' who is an expert in chemistry.
 * Jim Cummings as Peter Pete, Mickey's arch-rival who has a hatred for Mortimer but is on top of Mouseton's "Wanted" list.
 * R.D. Robb as Gangus Kahn, a member of Walter Cunningham's incompetent gang, the Kovacs.
 * Josh Gad as Dunbar Shoemeyer, a quirky friend of Elmer and Marius' who likes to fish play antics at times.
 * Daniel Stern as Martin Plymouth, the dumbest member of Walter Cunningham's gang, the Kovacs, who is never listening.
 * Liam Neeson as Principal Chesney, Elmer's understanding school principal who would be delighted to give Walter detention for misbehavior.
 * Demi Moore as Secretary Lerkel, Elmer's school's secretary.
 * Oliver Masucci as Herr Schmidt, Elmer's teacher.
 * Corey Burton as Chief O'Hara, the chief of the Mouseton's Police department.
 * Frank Welker as Figaro, Minnie's pet tuxedo kitten.
 * John Kassir as Bobo, Elmer's pet fancy rat.

Trivia

 * This is the first time Mickey and Elmer met since the 1934 black and white short film "Mickey Plays Papa", when Elmer was a baby.