Therese Belivet
Adulthood, it turns out, is not what Therese had imagined, and it does not seem to be something that she is naturally cut out for. Therese is just starting out and is already lonely and anxious. Her goal is to be a theater set designer, but she is working in the toy department of a large department store in New York whilst she waits for her big break.
Therese has a multitude of emotional issues, the main one of which is her lifelong feeling of abandonment. Her father died when she was very young and after his death her mother sent her away to a boarding school. Therese felt abandoned and has never managed to shake this feeling at all, which makes her relationships somewhat of a minefield, and also very intense and short lived.
Therese is a lesbian but not completely out yet; she is dating a man, Richard, but she does not love him on an emotional level, and is not sexually attracted to him. She is, however, immediately attracted to Carol Aird, the moment she sees her, and for reasons she does not herself understand feels compelled to reach out to her. Carol mistake her feelings for a schoolgirl crush, which is in part Carol's own attempt to deny her sexuality, but in part due to the very immature way in which Therese conducts herself whilst in a relationship.
Therese's abandonment issues make her quite unreasonable when it comes to Carol's predicament, as she expects Carol to prove that she loves her by choosing her over her daughter; this is both selfish and unrealistic; however, when the two are apart for a while, she realizes that she loves Carol and wants to be with her, and also gains the introspection to take responsibility for her role in the end of all of the relationships that have gone before.
Carol Aird
Carol is married to a rather unpleasant man, Harge, who sees marriage as a war of attrition rather than as a partnership. She has been unfaithful in her marriage, not with other men, but with her best friend, Abby. She is still in denial about her sexuality; she claims that Therese's feelings for her are nothing more than a schoolgirl crush, rather than serious romantic feelings, partly because she is trying to explain away the relationship between them as nothing more than a friendship.
Carol loves Therese deeply but is forced to end their relationship for the sake of her daughter, Rindy, from whom she is about to become estranged due to the legal action taken by her husband. She ends up the loser in both this battle and, temporarily at least, in her relationship with Therese, losing both of them in an effort to maintain ties with her daughter. When she and Therese are reunited, she realizes how strong her feelings are, and when given the opportunity to get back together, says yes immediately.
Harge Aird
An unpleasant and vindictive man, Harge cares less about his daughter's desire to maintain contact with her mother and more about his own need to hurt her after she admits to a lesbian affair. He is the kind of man who would find his wife having an affair with a man more palatable. He is furious about Carol's sexuality, and rather than discussing co-parenting in a way that best benefits their child, he is determined to punish her for being who she is, and for being honest with him about it. He views homosexuality as something deviant that can harm their daughter, and does not understand the nature of love. Although he is awarded full custody, his actions and his character demonstrate that he is certainly not the most suitable parent.
Richard
Richard is Therese's boyfriend, and his role in her life is that of company, as when she is first on her own in New York she is incredibly lonely. Their relationship is largely unfulfilling on every level.
