Daniel LaRusso

Single mother Lucille LaRusso uproots her only child, Daniel, from their home in New Jersey and moves them both to South Seas Apartments in Reseda, California. Daniel is invited by his new neighbor, Freddy Fernandez, to a beach party, where he meets Ali Mills. He also encounters and is beaten in a fight by Ali's ex-boyfriend Johnny Lawrence. During his first month in school, Daniel is constantly bullied by Johnny and his Cobra Kai gang. At the school's Halloween dance, Daniel attempts to get back at Johnny by placing a hose above the toilet stall where Johnny is rolling a joint, getting him wet. However, his scheme backfires, and he is chased by Johnny and his gang, who corner him outside his apartment building and assault him until Mr. Miyagi, the apartment's maintenance man, intervenes and saves Daniel. The next day, Mr. Miyagi confronts Cobra Kai sensei John Kreese and proposes that Daniel and Johnny settle their feud in the upcoming All Valley Under-18 Karate Championships tournament on December 19. Kreese agrees, but warns that if they do not show up at the tournament, both Daniel and Mr. Miyagi will be declared fair game to Cobra Kai.

Daniel is initially upset with Mr. Miyagi over the arrangement, but Mr. Miyagi assures that with proper karate training, he will no longer have to worry about Cobra Kai. However, Mr. Miyagi has Daniel do mundane chores at his rest house such as waxing his classic cars, sanding the wood floors, and painting the fence. Not understanding his teacher's methods, a frustrated Daniel threatens to quit, but Mr. Miyagi shows that the chores double as defensive techniques, which Daniel has learned through muscle memory. While training, Daniel develops a relationship with Ali. Mr. Miyagi also gives Daniel his yellow 1947 Ford Super De Luxe convertible as a gift on his 18th birthday and a reward for getting his driver's license.

At the tournament, Daniel unexpectedly advances toward the semifinals. Kreese instructs Bobby Brown, one of his more compassionate students and the least vicious of Daniel's tormentors, to put Daniel out of commission. Bobby reluctantly delivers an illegal kick to Daniel's knee, getting himself disqualified while Johnny looks at Kreese in disgust. Just before Johnny is declared the winner by default, Ali informs the tournament announcer that Daniel will fight in the final round. During the fight, Daniel gains the upper hand and gives Johnny a bloody nose. Kreese orders Johnny to sweep Daniel's leg, an unethical move. In fear of his sensei, Johnny hits Daniel's bad leg with an elbow strike and receives a warning from the referee. Upon the restart of the round, Daniel wins the match after landing a crane kick to Johnny's face. Having gained respect for his nemesis, Johnny gives Daniel the trophy. Daniel celebrates the victory as Mr. Miyagi looks on, proud of his student.[4]

At the beginning of the film, as Daniel and Mr. Miyagi are leaving, they see Kreese berating Johnny for placing second and strangling him. Miyagi intervenes and defeats him easily, comically tweaking his nose before walking away. Daniel asks why he didn't kill him, and Mr. Miyagi says "A person with no forgiveness in heart, living worst punishment than death." Six months later, Daniel returns early one morning to Mr. Miyagi's house from his senior prom dressed in a tuxedo and driving the now badly beaten up car Miyagi had given him. Surprised, Mr. Miyagi asks what happened, and Daniel angrily blames Ali for the damage and says that they broke up because she is in love with "a football player from UCLA". Later, when Daniel learns that Mr. Miyagi is going to Okinawa to visit his dying father, he uses his college fund to go with him. Upon their arrival, they meet Sato, a wealthy businessman and Miyagi's former best friend. Later, Daniel meets Kumiko, a teenager who aspires to move to Tokyo and pursue a career in dancing. He also encounters Sato's nephew Chozen Toguchi, and the two become enemies after Daniel inadvertently exposes the corruption in Chozen's grocery business. One day in town, Chozen challenges Daniel to chop a row of ice sheets; however, Daniel wins Chozen's wager by using Mr. Miyagi's breathing exercise and successfully breaking all of the ice sheets. Miyagi tells Daniel to keep his winnings for college. The Toguchi family continues to terrorize the village until a typhoon hits Okinawa. During the storm, Sato is pinned by debris from his family's dojo and rescued by Daniel and Miyagi, while Chozen runs away. Because of this, Sato lets go of his decades-old grudge with Mr. Miyagi and he offers to rebuild the village, disowning his nephew. A humiliated Chozen crashes the village's Obon festival, taking Kumiko hostage and challenge Daniel to a fight to the death. Daniel and Chozen fight a brutal and bloody back-and-forth fight, and Miyagi, Sato, and the crowd use their handheld drums to motivate Daniel and defeat his opponent with the Miyagi family drum technique.

Daniel and Mr. Miyagi return to Los Angeles from Okinawa to the discovery that their apartment building has been sold and is undergoing demolition, leaving Daniel homeless and Miyagi unemployed. Lucille is back in New Jersey to care for Daniel's uncle Louie. Mr. Miyagi invites Daniel to stay with him for a while, and Daniel uses the rest of his college fund to help his mentor set up a bonsai tree nursery. Daniel receives an invitation to defend his championship title at the next All Valley Under-18 Karate Championships, but Mr. Miyagi advises him to ignore it, seeing no point in the competition. However, Daniel is confronted by the prodigious and undefeated karateka Mike Barnes, who threatens Daniel into defending his title and steals the shop's bonsai trees. Terry Silver, a friend of Kreese and co-founder of the Cobra Kai dojo, offers to train Daniel for the tournament. Little does Daniel know that this is an elaborate scheme devised by Kreese and Cobra Kai to exact revenge on him by physically weakening him and having him suffer defeat at Barnes' hands. Silver hopes that this will revive Cobra Kai and promises to give Barnes partial ownership of the dojo in exchange for his help. Silver's methods start to corrupt Daniel, who becomes more aggressive and alienated from Miyagi. Realizing this, Daniel confronts Silver and tells him that no longer wishes to train under him, after which Silver admits that he set him up. When Kreese reveals himself and Barnes attacks Daniel, Mr. Miyagi saves his pupil and agrees to train him for the tournament.

At the tournament, Barnes swiftly advances to face Daniel in the final round. He uses Silver and Kreese's tactic of scoring a point, then losing it with an illegal move until they reach the sudden death round. After Mr. Miyagi prevents him from conceding the match, Daniel performs a kata in the sudden death round. A confused Barnes charges at Daniel, but Daniel flips him to the ground and strikes him to win the tournament.

Although Daniel does not physically appear he is mentioned several times by Miyagi. After accidentally walking in on Julie undressing he says "Miyagi apologize. You see, um, before, uh, live with a friend, Daniel-San. Daniel-San come Miyagi room, Miyagi go Daniel-San room. No big thing. Uh, boy is easier."

Later Miyagi quips "Miyagi have much to learn about girls. Boys easier.", referring to Daniel.

The series takes place 34 years after the first film. Now aged 50, Daniel is happily married to Amanda and has two children, Samantha (born 2002) and Anthony (born 2007). He and his wife own the LaRusso Auto Group, a chain of car dealerships in the San Fernando Valley. As part of the dealership chain's commitment to customer satisfaction, Daniel personally gives each new client their own bonsai tree. He unexpectedly meets up with his old nemesis, Johnny Lawrence, when his car is wrecked and sent to his intake lot. Daniel, unaware that his daughter Samantha was a passenger when her friends accidentally caused the wreck, offers to fix his car for free, considering Johnny an old friend. However, he later discovers that Johnny has reopened the Cobra Kai dojo in Reseda. Fearing that Johnny will create a new generation of bullies like those that he and Mr. Miyagi faced in the past, Daniel starts taking steps to undermine Cobra Kai. In addition, Daniel begins to struggle with issues within his family and business.[5]

Johnny's estranged son Robby Keene gets a job at LaRusso Auto Group to get back at his father. Unaware that Robby is Johnny's son, Daniel takes him in as his karate student. As such, Daniel proves to be a positive influence on the boy, and Robby later turns on his former criminal friends who plan to rob the dealership. However, upon learning of his student's parentage, Daniel furiously fires and banishes him. Undaunted, Robby participates in the All Valley Karate Tournament against Cobra Kai as an independent fighter, and the combination of this tenacity impressing Daniel and his wife convincing him to forgive the boy's mistakes leads to Daniel becoming Robby's sensei again. In the semifinals, Robby's shoulder is badly injured when Cobra Kai student Hawk attacks him from behind. Daniel coaches Robby the final match, but loses a close fight to Johnny's top student, Miguel Diaz, who fights dishonorably by exploiting Robby's injury. With teacher and student reconciled, Daniel plans to expand the Miyagi-Do style and philosophy with an official dojo to oppose Cobra Kai with Robby as his senior student.

Daniel opens the Miyagi-Do dojo and offers his lessons for free, threatening Cobra Kai's business. He takes Robby in as well, and proceeds to train him and Sam together. When he heads to Johnny’s dojo to tell him Robby is staying with them, he sees that Kreese has returned. Unfortunately, Daniel has trouble acquiring students considering they are not receptive to the chore-based muscle memory training style he used himself.

Daniel tries to be the bigger man after Cobra Kai upstages their demonstration at the local Valley Fest, even refusing to make use of footage of him dispatching of three purse-snatchers caught on Robby’s phone. He also takes on Demetri as a student, which proves challenging at first due to Demetri's constant whining and desire to take shortcuts. However, at the prodding of Kreese and without Johnny’s knowledge, Hawk leads a small group of Cobra Kai students in vandalizing Daniel’s dojo and his prized convertible, and stealing Mr. Miyagi's Medal of Honor. This pushes Daniel too far and he confronts Johnny at the Cobra Kai dojo, leading to numerous students walking out to join Miyagi-Do. Unfortunately, despite this success, Daniel's passion leads to him neglecting his auto business, forcing an irritated Amanda to run it alone, leading to loss of staff and declining sales.

Despite an uneasy reconciliation with Johnny, at the prodding of Amanda and Johnny's girlfriend, Carmen Diaz, the rivalry flares again after a misunderstanding caused by Robby and Samantha spending the night at Johnny's apartment after getting drunk at a party. To make matters worse, the animosity between the two begins to affect their respective students, and the growing tension between the dojos finally explodes into a massive karate war on the first day of school. As a result, Samantha is hospitalized and Johnny's favorite student, Miguel, is inadvertently seriously injured by Robby and placed in Intensive Care. This event also allows Kreese to take control of Cobra Kai and force Johnny out. A furious Amanda demands that Daniel close down the dojo and stop all karate activities. Feeling that he has tainted Mr. Miyagi's legacy, Daniel sadly obliges.

Reeling from the fallout of the school fight, Daniel's reputation has been tarnished, causing his car dealership to struggle, and also has to handle Sam's lingering trauma. Daniel and Johnny briefly team up to find Robby, but go their separate ways after defeating a group of car thieves. Daniel finds Robby at Shannon's rehabilitation facility and has the police take Robby into custody in order to lessen his sentence. Robby angrily accuses Daniel of betrayal and tells him to not visit him in juvenile hall, ending their friendship. Upon learning that his business rival Tom Cole had a hand in dissolving his business partnership with Doyona International, Daniel heads to Tokyo in order to salvage his business. Discouraged by his failed negotiations, and after an inspirational talk with a local bartender, Daniel visits Tome Village, where he reunites with Kumiko. After telling her of his personal and business problems, Kumiko gives Daniel closure by reading him one of Mr. Miyagi's final love letters to her aunt Yukie, and also arranges him a meeting with Chozen in order to reconcile. After a few sparring sessions, Chozen gives Daniel a martial arts move scroll describing pressure point techniques. Daniel's business partnership is saved when he learns that Yuna, a little girl he saved from a typhoon is the Vice President of Sales for Doyona.

Upon returning from his trip, Daniel opens up to Sam and gives her a lesson about overcoming her fears. With Amanda's support, Daniel re-opens Miyagi-Do, and attempts to bring down Cobra Kai through legal means, but fails. When the local city council cancels support for the All Valley Karate tournament, Daniel attempts to make a case for re-opening it, but is rejected when there are visible displays of contempt against Kreese. Miguel and Sam make a surprise appearance and persuade the city council to re-open the tournament. Daniel eventually reunites with Ali during the Christmas holidays and introduces her to Amanda, unaware that Ali had invited Johnny along as her "date." During their dinner together, Ali offers a different reason for their breakup than the one Daniel gave in The Karate Kid Part II. She says that Daniel saw her talking with someone she knew at UCLA and jumped to the wrong conclusion. They reconcile over this misunderstanding, and Ali prompts Daniel and Johnny to put aside their differences. Taking her advice to heart, Daniel saves Johnny's life after hearing of Cobra Kai's attack on his home and defeats Kreese, barely sparing Kreese's life. Kreese, Johnny, and Daniel agree to temporarily cease hostilities in order to train for the tournament.

Finding common ground with Johnny, the pair train together with their students at the Miyagi dojo.