Siyeon, who returns home after studying abroad for college, finds out about the 'Understanding Wine' course that her younger sister has picked for her.
It's very popular because it's about tasting wine, but Siyeon is a lightweight that can't drink alcohol!
When she decides to correct the course and attended it, she is reunited with her high school friend Eunha... !?

(Source: Bomtoon, translated)