Eunhoo menghilang seperti asap setelah menghabiskan malam bersama. Taeyeon tidak bisa melupakannya, dia adalah kekasih pertama dan cinta pertamanya. Tapi apa ini? Eunhoo tinggal di sebelah. Ya! dan juga... Dengan bayi laki-laki imut yang mirip dengannya! Itu Eunhoo, yang sangat dia cari... Tapi apakah dia sudah punya pasangan? Eunhoo disappeared like smoke after spending a night together. Taeyoon can't forget him, he was first lover and his first love. But what is this? Eunhoo lives right next door. Yes! and also... With a cute baby boy who looks like him! It's Eunhoo, whom he was looking for so much... But does he already have a partner?