Junpei Kousaka is a second-year high school student who suffers from a cat allergy—a situation that has led him to despise cats and anything associated with them. Unfortunately for him, he is surrounded by cat enthusiasts: his family, his estranged childhood friend, and even his crush, Kaede Mizuno. One day, on his way home from school, Junpei casually tries to kick an empty can into the trash bin but misses completely. Instead of landing in the garbage, the can strikes and breaks the head off a statue of a cat deity. On that fateful day, he is cursed with the ability to understand cat speech. However, he must keep this curse secret from everyone else, because anyone who discovers the truth will become more accident-prone and share his same fate. Guided by his cat Nyamsus and with no other option, Junpei must now perform one hundred good deeds for cats to lift the curse. If he fails to complete this task, he will turn into a cat, and given his allergy, that would be a death sentence for him!