A high schooler wakes up one morning turned into a dog, and is promptly taken in by his cool, expressionless classmate Karen Inukai, who has no idea her new pet is a boy from her own class. At school Karen barely shows emotion, but at home, with the dog she has named Pochita, she turns out to be affectionate and doting in ways her classmates would never guess. He wants to find a way back to being human, but living inside Karen's daily routine keeps giving him reasons to put that off.