The series stars Gary Coleman and Todd Bridges as Arnold and Willis Jackson, two African American boys from Harlem who are taken in by a rich white Park Avenue businessman named Phillip Drummond and his daughter Kimberly, for whom their deceased mother previously worked. During the first season and first half of the second season, Charlotte Rae also starred as the Drummonds' housekeeper, Mrs. Garrett.
A family whose little boy died, forces the father to kidnap Sam, who is shopping for some snacks in a grocery store. After the kidnapping, the man threatens to kill Sam's parents if he attempts in any way to escape.
The Drummonds, desperate to get Sam back, go on the news to try and advertise to get Sam back. In the meantime Sam risks everything to tell the Drummonds where he is.
Guarding the school bully's girlfriend, Ramona, seems like a simple task to Arnold, until his natural Jackson ""charm"" creates some problems, Ramona falls head over heels for him and Herman, the bully, wants to rearrange his face.
Sam and Arnold fear that the time their parents are spending apart is a symptom of an ailing marriage and the boys attempt to give them a dose of romance, hoping it will be the cure that will keep them from divorce.
Willis takes a big step when he leave home for college, but fears his initiation to dorm life is only one of the freshman experiences he may not be ready to handle.
Arnold's dream of becoming an ""overnight"" success as a photo-journalist run headlong into reality when he gets his first job on a local newspaper.
Kareem Abdul-Jabbar guest stars as a high school English teacher who gives Arnold a ""classic"" punishment for ""goofing off"" in class and the freshman quickly learns his lesson when his penace is teaching ""A Tale of Two Cities"" to his rowdy classmates.
A music instructor ""backs up"" Arnold after he claims to be an expert sax player in order to impress a girl.
Father and son are feuding over First Amendment rights when an outraged Arnold objects to a white supremacy organization speaking at his high school and a discerning Drummond can't support Arnold's fury on the basis of the American right to free speech.
Arnold succumbs to peer pressure and boasts he went ""all the way"" with his girlfriend, but his lie puts him in a more awkward position once the girl finds out about his claim to fame.
Drummond has ""insured"" that Sam will have an unforgettable birthday party by arranging for a local television personality to be the main attraction, until the swash-buckling ""Captain Jack"" steals the show and the birthday boy jumps ship.
Arnold's initiation into the ""cool"" club at school jeopardizes his friendship with the mildly-retarded dishwasher at the Hamburger Hangar, after a prank Arnold ""must"" pull causes the man to lose his job.
Arnold suspects that Kimberly has an eating disorder when his slender sister is secretly gorging himself, but not gaining any weight. Arnold seeks Drummond's help in confronting Kimberly with her problem and the family comes together to help her fight the eating disorder, bulimia.
Arnold's preoccupation with girls and school leaves younger brother Sam alone and bored until Willis steps in, takes over as ""big bro"" and causes a row when Arnold decides to fight back for the title.
To prevent Drummond from seeing his ""F"" in geometry, Arnold arranges to have Drummond's signature forged on his report on his report card, but the scheme backfires when Drummond insists on a personal inspection of Arnold's grades.
Sam's contempt for a classmate who incessantly insults and badgers him is pacified when he learns that the boy is an orphan who's jealous of Sam's ""perfect"" family life.
A date with a gorgeous girl has Arnold walking on a cloud, until he learns she was bribed by Willis to go out with him.
Arnold is disgruntled over being partnered with archenemy Lisa in photography class but his frustration soars when the two are accidentally locked together in the basement darkroom.
Arnold's feature story about his high school football team threatens to turn into a controversial expose for the school newspaper when he witnesses team members buying steroids.