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Jack Brewer
Jack Brewer (Leo Howard) is the new person in Seaford, whose foremost hobbies are martial arts and skateboarding. He learned karate from his grandfather, who also trained Bobby Wasabi for his movies. He is loyal to his friends and inspires them to give 110%, just as he himself always does. He cannot stand the scent or taste of bleu cheese and also has a phobia of clowns, which he confronted in "Boo Gi Nights". He has great respect for his elders, particularly Rudy, but dislikes being told what to do and being shoved away. He gets jealous when Kim goes around other boys, as seen in "New Jack City". He has skills in martial arts that far surpass those of his friends.
In "Buddyguards", it is revealed that Jack can play guitar. In "Hit the Road Jack", he is offered a chance to go to Japan's Otai Academy; however, he declines since he does not want to leave his friends. In "Kickin' It on Our Own", he and Kim go on a date, and they later begin officially dating in "Two Dates and a Funeral". In "Wasabi Forever", he encourages Kim to go to Otai Academy, and she gives him a cherry blossom to remember her by.
Milton
Milton David Krupnick [1] (Dylan Riley Snyder) is an honor student who enrolls in martial arts to learn self-defense after being bullied. He is oddly unaware of his own shortcomings and has an awkward sense of confidence. A child prodigy, most school subjects come naturally to him. He has a weird sense of nerd fashion, and once gets food for the dojo when it is about to get smashed. According to his parents, he looked like a baby bird when he was born. He takes pride in having won his school's first-ever spelling bee. His girlfriend is Julie, but he later reveals in "Gabby's Gold" that they broke up. Since their breakup, he becomes overconfident and usually comes on too strong. In "How Bobby Got His Groove Back", it is revealed that he is Jewish.
Jerry
Jerry Martinez (Mateo Arias) is a lone wolf who ends up at Bobby Wasabi Martial Arts Academy to complete his school PE credit. He speaks Spanish fluently, despite flunking his high school Spanish class, and acts as a bad boy to give himself the illusion of being macho. As a talented dancer, he once invents a move called "The Jerry". While he is more confused than tough, he is fiercely loyal and takes his friendships very seriously. He is willing to try anything at least once and seldom refuses a dare. He has become a better karate student than both Milton and Eddie, as seen in "All the President's Friends", when he fights Frank. He originally works at the Seaford Animal Park, but in "The Boys Are Back in Town", he becomes the manager of Falafel Phil's Bowl and Burger, where it is also revealed that he is a skilled bowler.
In "All the Wrong Moves", it is revealed that his last name is Martinez. In "Reality Fights", it is revealed that Jerry is frightened of saltine crackers. In "Skate Rat", Eddie reveals that Jerry's middle name is Caeser. In "The New Girl", Jerry is revealed to have a lying problem which Milton and Joan try to cure him of, until they realize he is more trouble when he tells the truth, which is also the reason for Milton and Julie breaking up.
Kim
Kim (Olivia Holt) is a former Black Dragon, who crossed over from the Black Dragons after they cheated in a tournament. She loves journalism and hates being called just another pretty face. She rarely wears dresses or makeup, except to impress boys. She is co-captain of her high school cheer squad and had a huge crush on teen pop star Ricky Weaver, until he proved to be an utter heel. She is typically the first to stick up for herself and her friends. She has a crush on fellow black belt Jack, but hides it from him and everybody else.
In "Dojo Day Afternoon", it is revealed that Kim's last name is Crawford. In "A Slip Down Memory Lane", it is revealed that she considers Jack as more than just a friend. In "Wazombie Warriors", she goes on a date with Jack. In "Karate Games", she tells Jack that he is amazing and he almost kisses her. In "Kickin' It on Our Own", she and Jack go on another date. In "Jack Stands Alone", it is revealed that her middle name is Beulah. In "Two Dates and a Funeral", she and Jack begin officially dating. In "Wasabi Forever", she is accepted into Otai Academy and leaves for Japan. After sharing a kiss, she gives Jack a cherry blossom petal to remember her by.
Eddie
Eddie (Alex Christian Jones) is a sweet and uncoordinated youngster who attends Bobby Wasabi Martial Arts Academy to get in shape. He loves the sense of achievement karate gives him. His biggest fear is that if the dojo ever closes, he will be forced by his mother to go back to Mrs. King's Dance Academy. His pet peeve is doing anything he detests, like taking dance or cello lessons, for the sole purpose of impressing others. He embarrasses easily and was once blackmailed by school bully Truman into pulling a series of cruel pranks on his friends. He wants to be an archaeologist when he grows up.
Rudy
Rudy (Jason Earles) is a third-degree black belt and the sensei of Bobby Wasabi Martial Arts Academy. He was a top amateur martial artist until being sidelined by an injury. He has used his entire life's savings to become co-owner of the Bobby Wasabi Martial Arts Academy chain and takes fierce pride in the fact. Despite his wacky nature and sometimes gross sense of humor, he is a very good, if unorthodox, karate instructor who genuinely identifies with his students and is always ready to back them up when times get rough. After becoming Sam's guardian, Rudy makes Jack his assistant sensei.
In "It Takes Two to Tangle", his last name is revealed to be Gillespie. In "Kickin' It on Our Own", he sells the dojo, but gets it back after winning a match against Kofi Kingston. In "The Boys Are Back in Town", Rudy opens the Wasabi Warrior Academy after a Ferris wheel accident.
