Eddie meets a newly-arrived young starlet, Dolly Daly, during an MGM studios tour, and invites her home to stay with him and Tom - his "kind, generous, and handsome father". Her presence in the home leads to wild speculation by both Mrs. Livingston and Norman, who Tom has recently been forced to fire due to his missed deadlines. During an argument between Mrs. Livingston and Tom over Dolly, eggs are broken and Mrs. Livingston then quickly leaves the apartment. Eddie is convinced she has left them for good. Tom is feeling overwhelmed with all his problems, and loses his temper with Eddie when he begs Tom to go after her. Dolly proposes that she can take Mrs. Livingston's place for a while, and that Tom can put her picture on the cover of his magazine in lieu of payment. Tom realizes that he has found a way to get rid of Dolly and give Norman another chance at the same time.

Tom receives a mysterious note from Eddie's teacher, Miss Allen, saying she wants to discuss him. Fearing the worst, he goes to the school to meet the teacher. He's doubly pleased when he finds out that not only is Eddie a very bright student, but his teacher is young and attractive. The two hit it off immediately, and begin dating. The relationship between his dad and his teacher causes problems for Eddie, who is dubbed the "Teacher's Pet" by his classmates. After Eddie gets in a fistfight with some other boys over things they have said about his father and Miss Allen, Tom and the teacher are forced to reconsider the impact of their romance on Eddie.

Tom is close to proposing to his girlfriend, Lynn Bardman. When Eddie catches a cold and Mrs. Livingston can't take care of him because she's also ill, Tom asks Lynn to play nurse to Eddie for the day. She finds the responsibilities of caring for a child and running a household to be more than she bargained for, however. At the end of the day, Lynn wonders if she is ready to be a good mother to Eddie.

Eddie decides it isn't fair that Mrs. Livingston is all alone in the world. After precocious Eddie goes into a lengthy explanation about pollenation, he stuns his dad by suggesting that he pollenate Mrs. Livingston - so she can have her own little boy. Tom quickly nixes the idea, but Eddie is determined to provide her with a child. He brings home ("kidnaps") Frank, the perfect Japanese boy he found at school, and announces to a bewildered Mrs. Livingston that he's her new son. The boy's separated parents are brought together when they find their child at the Corbetts'. Tom then lends a listening ear to Frank's father, who is troubled over his crumbling marriage and distant relationship with his son.

Norman convinces Tom to try computer dating - to "bravely submit to mechanizing his libido" - in order to get first-hand information for the magazine article Norman is writing. Tom's computer date, Diane, turns out to be a better match for Eddie than for him, however. Since Eddie is so fond of her, Tom decides he should give her another chance - to see if they are "computable". While Tom stays home with a cold, Diane takes Eddie to her office to see the computer and lets him fill out a dating questionnaire for demonstration. When the computer matches Eddie to her, she and Tom realize why they had been paired up, also.

Eddie is reluctant to attend his first day of school, and refuses to stay once he arrives. Although Tom finally convinces Eddie he must return the next day, the transition still proves to be difficult. When a bully makes fun of the fact that Eddie has no mother, Eddie strikes the boy and ends up with a black eye. Tom feels he should protect Eddie from the world a little while longer, and get him a tutor - until Mrs. Livingston points out that this would be unwise. He then decides to use reverse psychology to make Eddie want to go to school. Tom announces to Eddie that he will teach him at home with a rigorous course of study. The plan backfires at first, until Tom plays his trump card - he tells Eddie they will no longer be able to afford Mrs. Livingston if Tom gives up his job to teach him.

Eddie wants to invite his new, fatherless friend, Max, over for the weekend. He plays matchmaker for Tom, suggesting that he invite Max's mother, Betty, over for dinner as she drops Max off. Eddie feels she would make a great date for Tom, as she is beautiful, and a "full-grown mother" who is "already broken in". Tom agrees to be set up on this blind date, and invites over both Max and Betty. When Max and his mom arrive at their apartment, however, Tom is surprised to find that Betty is not what he expected.

Eddie has been having trouble with a bully at school named Joey Kelly, and refuses to fight back even after Tom teaches him the fine art of self-defense through boxing techniques. Tom is puzzled about Eddie's reluctance to defend himself, until he is called to the school and discovers the identity of the bully. When Tom realizes Joey stays at home alone after school, he invites her to their apartment - much to Eddie's dismay. Tom feels that Mrs. Livingston is just the woman to refine the little tow-headed tomboy. During dinner, she teaches Joey to serve Tom and Eddie Japanese-style. But Joey grows increasingly indignant at having to serve Eddie and wait for her own dinner, and finally explodes. Eddie then must decide whether he will follow his father's orders never to hit a girl, or if he will follow Mr. Kelly's advice and "belt her back."

Spring is in the air, and Mrs. Livingston has been very distracted lately. Tom discovers it's because there is a new man in her life, and he tries to find out all he can about the Japanese businessman, Mr. Sato. When Mr. Sato asks Mrs. Livingston to become his wife, Eddie is upset - he knows this means she will no longer be taking care of him and his father. Then Mr. Sato announces that he and Mrs. Livingston will have to move back to Tokyo after the wedding, causing Mrs. Livingston to reconsider the proposal.

An old college aquaintance of Tom's - Harvey - appears at the Corbetts' front door. Eddie thinks his father's friend is both fascinating and fun, but Tom is annoyed with Harvey's constant reminiscences of their college days and his immature antics. Due to Eddie's pleading and Harvey's manipulation, Tom unenthusiastically invites him to spend the night - which turns into several. Eddie generously gives up his bed to Harvey, telling Tom he wanted to do it because he's such a good friend of his dad's. Tom then finds it awkward to ask Harvey to leave even after he takes advantage of the Corbetts' generosity and wears out his welcome. When Harvey suddenly announces his departure, his kind gestures toward all of them teach Tom an important lesson in friendship.

Mrs. Livingston failed her English test, causing Eddie to think she will commit hara kiri to save face.

Tina proposes to Norman.

An overnight camping trip leads to a Corbett-Lockwood quarrel.

Tom tried to take Eddie's mother's place at a school party.

Eddie's flamboyant Aunt Kate comes for a visit.

Eddie loses the very first library book he takes out.

Eddie is suffering from a case of puppy love

A retired school teacher unknowingly alienates Eddie from his father.

Eddie has a crush on his babysitter, who has a crush on Tom.

Mrs. Livingston departs, leaving Eddie and Tom alone.

Tom tries to find a future guardian for Eddie.

Tom tries to prevent Mrs. Livingston from being deported.

Norman has to lose five pounds in two days.

Tom has been ordered by his boss to fire his best friend

Tom's nutty secretary has become interested in astrology and quits her job.

Eddie finds ten thousand dollars.