Moggina Manasu focuses on the confused state of mind of teenage girls and their relationships with boys. It also touches on teenage pregnancy and ragging in colleges, camaraderie with seniors, and teenagers' disrespect towards their parents and studies. The film tells the stories of four teenage girls and the trials and tribulations they face during their college time. Chanchala goes to the college. It was her first day, and she was ragged by her seniors Akka and Didi as Chanchala calls them . Another village girl Renuka Devi often called as Renu also comes to the college. She wants to be a Doctor and treat her village people. Later akka, Didi, Renu and Chanchala becomes best friends. Akka and Didi change Renu and Chanchu completely. Renu and Chanchu feels that they need a boyfriend. Chanchu loves her English teacher but later comes to know she should not. Renu gets a boyfriend Akash and chanchu is also persuaded by a person to love her. Later they love Each other. but that man tries to avoid her in her activities. He refers her as public Property which angers her and she leaves him. Later enters Rahul, a singer who loves her more than his life. Even she starts loving him. Later Renu gets Pregnant because of Akash. He tells her to abort the child. She doesn't want to. She tells this to Chanchu and Didi who scolds her. Didi tells that all men are cheaters and she lost her sister as her sister was cheated by a man. Chanchu listens to all this and Talks about this with Rahul. Next day Renu is found Hanging. Renu's death changes Chanchu's mind. She breaks up with Rahul. After many years she was going back to Mysore where she studied . In the train she remembers all this. She meets Akka whose life was settled. Akka had run away with her boyfriend and marries which had angered her father and her mother died of this. But now her father, her husband and her daughter. Chanchu is Happy to see them together. She goes to the college where she studied with Akka as Old students association function had been held. There she meets Didi who had also married an led a settled life. They remember Renu. Later Chanchu remembers Rahul. Just then she hears Rahul's voice from Auditorium. She hurries there. Later there is a song program by him in memory of her. She thinks of going to him but thinks that he may have forgotten her and married another. But after the song Rahul tells that he had lost his love but now he is getting it back. He tells them that he is going to propose the girl he loves in front of them. He proposes Chanchala in front of everyone. She is astonished and happy. Yash's parents and Chanchu's parents also agrees to their marriage as they loved each other even after so many years. They get married.