Young actress Joo Arin is set to make her big-screen debut, but while preparing for the role, she comes across a bit of a problem... She has to film a kiss scene even though she hasn't even had her first kiss yet! As Arin struggles to practice for the shoot, top star Kang Hajun, who happens to be with the same agency, decides to help out by teaching her how to kiss. As she starts these special secret lessons, Arin's finding it hard to tell if she's more immersed in the role or in Hajun.