The series begins as an over-educated Diane Chambers enters the Cheers bar with her fiance/boss, Literature Professor Sumner Sloane, for a quick drink while he makes a phone call to get his mother's wedding ring from his ex-wife. But when Sumner goes to his ex-wife's house to get the family ring for Diane, his relationship with her gets rekindled. Upon his return, he tells Diane that he has no intention of leaving her, and returns once more to get the ring he was supposed to get the first time. This time, he ends up taking his ex-wife to the Barbados to get (re)married, abandoning Diane without a word.
A crushed Diane is left jobless, with few prospects, and finds that a waitress job at Cheers may be the right thing for her.
After Diane mocks Sam's many female conquests for their lack of intellect, Sam sets out to prove he can attract intelligent women, too. Meanwhile, a long-past patron of the bar comes looking for advice from one of the former owners. Since that owner is long-since passed away, it falls to Coach Ernie to render advice.
Carla loses her temper after a Yankees fan begins to insult Sam, and she attacks him. Now the fan plans to sue Sam and take the bar away unless Carla can learn to control her temper.
A local big shot newscaster asks to interview Sam, which boosts his ego, but Diane doesn't think that agreeing to put himself on television is a good idea.
Coach's daughter comes to Boston with some big news, she's getting married! But the man of her dreams turns out to be an obnoxious moron. Coach doesn't have the heart to tell her, which causes a strife in their communications.
An old friend of Diane's comes to visit her on the rebound of her latest loss at love. Diane becomes upset with Sam after he tries to hit on her friend.
In order to kiss up to the boss Norm takes on the planning the annual office party and of course holds it at Cheers. But in order to make this night complete he will need to find his boss a date... I wonder where Diane is.
Diane insists that she and Carla stay after closing to settle their differences once and for all, but one too many drinks makes Carla reveal the startling "truth" about her youngest child.
Coach gets a thing for his new neighbor but after Sam see's her he also gets his eyes on the prize.
One of the Red Sox players comes into the bar and is very frustrated with a slump he is in. He asks Sam for advice, and Sam brings up his lucky charm - a bottle cap. The baseball player wants to borrow it for luck, and Sam is very protective about it, but ends up letting him borrow it. Sam is very upset when the player does not return it within the promised time period.
Diane begins to keep notes on conversations of the bar; in the meantime a man who is about to join the monastery stops by the bar and after a few drinks reveals some deep secrets about his life, as the gang tries to cheer up an old WWI veteran whose buddies seem to have missed their reunion.
A mysterious quiet fellow enters the bar and doesn't say a thing all day; which makes the gang believe he is a secret agent.
Sam lets the sexy appeal of an agent and the glamour of the public spotlight lure him into being a TV pitchman.
After Diane's cat dies she turns to her bar friends looking for help, but ends up very dissapointed when they ignore her for the Celtics game.
Carla is pregnant... again, and lets another man believe he is the father because he is smart and could provide for her.
Cheers' regulars fear the place may become a gay hangout after an old friend of Sam's reveals his homosexuality on TV.
Sam and Diane make a bet that they can find each other dates within the next 24 hours. Diane finds the perfect date for Sam, but Sam thought Diane was talking about being Sam's date when they made the contest. He ends up finding a man at the bar in the pool room, and pays him to be Diane's date. Little does Sam know, the guy he paid to take Diane out was an ex-criminal.
Sam enters Diane into the Bar Maid contest. Diane has no idea, she sees her picture in the paper. She threatens to quit, until she finds out that the newspaper and radio shows will be giving interviews to the winner. She stays in the contest, only to win, thinking she will explain how Bar Maid contest are absurd and disrespectful to women. This all backfires on her when she wins, and gets to go to Bermuda.
After Coach is cheated out of a lot of money Sam turns to Harry (the conman) to help get it back.
Diane's mother shows up at Cheers with some bad news: If Diane doesn't marry before the next day her mother will lose the share of Diane's father's estate.
Diane's fascination with Sam's older brother brings their long simmering relationship to a boil when the sibling asks Diane to go to Paris with him.
Diane's fascination with Sam's older brother brings their long simmering relationship to a boil when the sibling asks Diane to go to Paris with him.