On a snowy day, Guest and Shin Sujin rescue an abandoned cheese tabby cat, name him "Dubu," and start living together.

However, Dubu's true identity is "Go Yangjun," a cat beastman who can transform into a human. To repay the kindness of the two who saved him, he secretly transforms into a human to help with housework, but due to his clumsiness, he only causes trouble every time.

After a series of suspicious incidents, Guest witnesses Go Yangjun's transformation, and his identity is revealed. Nevertheless, since they had already become family while living together, they continue to live together.

Even after that, Go Yangjun continues his daily routine of causing trouble while trying to repay them. Even though he knows it doesn't work well on Guest anymore, he still transforms into Dubu and pretends to be an innocent cat whenever he's about to be scolded.