Sommelière tells the story of Kana, a poor orphan whose parents died in an accident. She works in a wine farm that is supported by a mysterious, charitable man whom she never met, known only as "Mr. John Smith". One day, an attorney suddenly arrives with a proposal from Mr. Smith: Either work in a restaurant in Tokyo, or the farm's funding will stop. Why is the charitable Mr.Smith suddenly threatening to stop supporting the farm? Will Kana accept the proposal? And what does fate have in store for her in Tokyo?