Sung-jun is a young man working at a pet café for mostly abandoned animals. He one day runs into a seemingly abandoned dog on his way home from work. Sung-jun adopts the dog and names him 'Tan', not knowing how this decision will change his life completely. Upon waking up from sleep, Sung-jun gets startled by a male stranger lying next to him, only to find out that man is actually Tan. From that day onward, every pet animal Sung-jun meets in the streets and at work appears to take human forms in his eyes. While Sung-jun tries hard to adjust to this entirely new environment, he can't help but feel that Tan (or at least Tan's human form) is turning out to be more than just a pet to him...

This is a story about an unlikely romance between a pet-loving young man and his supposedly adopted dog who seems to be just too human to be anyone's pet.