Taeyeon and Tiffany work in the same building, the same floor yet different department. Taeyeon works as the script writer for anime movies while Tiffany works under Yuri's command as a voice actress and sometimes she sings the songs for the original soundtrack needed for the movie. Both of them love each other but Tiffany’s pride is too high to confess while Taeyeon is too afraid to confess. Taeyeon always feels safe because up until now, no man can last more than 3 dates with Tiffany. Unfortunately that can’t last long, because a guy suddenly came out of nowhere and tried to snatch Tiffany from Taeyeon. He has succeeded in taking Tiffany into dates for more than 3 times. Taeyeon feels insecure and thinks that she needs to do something to prevent the guy from taking Tiffany away from her. An idea crossed her mind and with that idea, she is planning to change the term of best friends into lovers. With help from Sooyoung, Yuri, and Sunny, Taeyeon hopes she can claim Tiffany as hers and hers only.