Doris simply wanted to open a refined, stylish coffee shop in a bohemian Taipei neighborhood, but when she's stuck with a load of useless gifts from the opening celebration, her younger sister Josie turns the café into a burgeoning bartering business. There, even a soulful song (by Japanese singer Atari Kosuke in a cameo) is a tradable commodity. One day, a traveler brings in 35 soaps from around the world with a story for each of them, awakening Doris' imagination about the outside world that she has never seen.

Sheng Enterprise has originated from a famous Mahjong family, and the story of Big Three Dragons begins with the game of Mahjong.