Meow, the Secret Boy bercerita tentang Kim Sol Ah (Shin Ye Eun), seorang gadis yang tinggal sendirian, kebetulan dia membawa pulang seekor kucing Hong Jo (L / Kim Myung Soo). Kim Sol Ah tidak tahu bahwa Hong Jo bukan kucing biasa. Dia memiliki kemampuan untuk berubah menjadi manusia.
Sementara itu, Kim Sol Ah lelah dengan situasinya yang sulit dan membawa luka emosional. Saat tinggal bersama Hong Jo, Kim Sol Ah sembuh secara emosional.
A graphic designer in her mid-twenties, Sol Ah harbors dreams of becoming a web-based comic author and has always had a love-hate relationship with cats.
But Sol Ah’s life changes fast when she brings home a friendly feline. It turns out, however, that this is not any old cat. Named Hong Jo, he can take human form. Hong Jo becomes exceptionally fond of So Ah, and goes to great pains to hide his human identity from her. He soon proves that he will do anything that is required in order to stay near her.
Will Hong Jo manage to keep his identity a secret?
And what could be in store for this remarkable feline-human duo as their relationship deepens?