Tony Leung is a night school instructor who also drives a taxi when he is not working. He lives with his two fathers Ha Yu and Lau Dan. They each claim to be Tony's father. Because Tony's mother died while giving birth to him, there was no way of finding out who his real father is and they never bothered to find out after a while. And so they have been raising Tony together and living like the Odd Couple with Lau Dan being the neat and meticulous guy and Ha Yu the unkempt and sloppy one.

One day while driving his taxi, Tony encounters Barbara Yung who was chasing after a prostitute. He mistakes Barbara for a prostitute when in fact she is a cop. When they meet again at the police station to settle a dispute between Tony's fathers, Tony finally realizes that Barbara is a cop.

One of Tony's students gets into trouble with the law and Tony seeks the help of Barbara's dad who works at a law firm. He recommends Chan Mun Yee to be their defense attorney. During the course of their working together, Tony and Chan Mun Yee become good friends.

Chan Mun Yee lives with her mother who suffers from kidney problems. Her father had deserted them a long time ago but he has since become destitute and often comes back to harass Chan and her mother for money.

Tony later resigns from his teaching job to work for a jewelry company owned by Kwan Hoi San. There, he gets to know Lui Leung Wai who is Kwan's maternal grandson.

Meanwhile, Ha Yu and Lau Dan are fighting over Au Yeung Pui San. She used to live in the apartment that they are living in but her boyfriend had sold the apartment while she was in Japan leaving her with no where to go upon her return to HK. Out of sympathy, Tony and his fathers invite her to stay with them until permanent arrangements can be made. But it doesn't take long for both his dads to start falling for her and start a comical love triangle.

Tony and Barbara soon fall for each other but Tony's fathers don't like her because her father had helped Au Yeung Pui San's boyfriend sell her apartment without her knowledge. On the other hand, Chan Mun Yee is starting to develop feelings for Tony while Lui Leung Wai is actively pursuing her.

When Chan Mun Yee confesses to Tony about her feelings for him, he turns her down citing his love for Barbara. Lui Leung Wai is able to move Chan Mun Yee into marrying him when he buys her mom a dialysis machine and even gives up one of his kidneys for her.

Kwan Hoi San later learns that Lau Dan is his long lost son by his first wife. A reluctant Lau Dan moves in with Kwan's family only to find himself ridiculed and despised by his half siblings. Unable to get used to the lifestyle of the rich, he moves back home but encourages Tony to stay on and look after Kwan Hoi San.

Barbara is hesitant about continuing his relatonship with Tony when she learns that Tony is now the rich grandson of Kwan. She is afraid that other people will think she is in for the money. Fortunately, Tony is able to convince her otherwise.

Kwan's eldest son has been getting away with embezzling company fund. He sees Tony as a threat to his interests and tries to undermine Tony and Lui Leung Wai's relationship by stirring up sibling rivalry issues between them. Together with Lui Leung Wai's mother, they manage to convince Lui that he has to prove himself soon or Kwan Hoi San would favor Tony over him because Tony is Kwan's paternal grandson while Lui is only his maternal one.

Lui begins to distant himself from Tony and makes several bold business decisions on his own causing the company to lose big money. After Kwan Hoi San's death, he is even tricked into selling the company to his uncle.

Guilty at what he has done, Lui vows to seek revenge on his uncle. Working as a spy at what is now his uncle's company, he secretly gathers evidence of embezzlement against his uncle and is able to redeem himself when his uncle is finally arrested for fraud.

In the end, Tony and Barbara manage to convince his fathers to accept her. As for Au Yeung Pui San, she chooses Lau Dan over Ha Yu but it doesn't take long before Ha Yu finds new love again.