Miu Chun (Gallen Lo) was once diagnosed with cancer, and became really depressed. Cheung Ka-Ka (Tracy Ip), a nurse, comforted him and later became his girlfriend. Soon after he recovered, the two adopted a cat, Can Can, and a dog, 大巴 (Dai Ba). One day 大巴 ran across a road, Ka-Ka tried to rescue the dog from an oncoming car but died in the accident herself. From that day on Chun hated dogs and abandoned Dai Ba.

Chow Chi-Yu (Myolie Wu) found 大巴 wandering on the streets and brought him back to her father's kennel. However, 大巴 carried a deadly virus and killed all the dogs at the kennel. Since then, Yu's father became employed with the pound to catch abandoned dogs. Her brother, Chow Chi-Jim (David Lui), and sister-in-law, Shui Tin-Lan (Margie Tsang) opened a pet shop to earn money for the family.