Jiho, a being torn between his human and fox heritage, faces a peculiar challenge to embrace his human side – he must spend a night with someone who ingests a magical, ancient marble. But his well-laid plans to meet a cute girl are upended when Gunwoo, a man, accidentally becomes the marble's keeper. While Jiho's initial deceit gradually turns into genuine affection, Gunwoo remains unmoved by his advances. Will Jiho be able to seduce the resistant Gunwoo and become fully human?