In the seventh year of the Zhenguan era, modern young man Xu Mo wakes up transported to Chang'an in the Tang Dynasty. He inherits a shop in the Eastern Market and binds himself to the "Strongest Supermarket" system, which allows him to sell modern products such as spicy strips, facial masks, bread, and refined salt. On the first day of business, Li Shimin and Cheng Yaojin, out in disguise, wander into the Great Tang Supermarket, where the spicy strips cause a hilarious misunderstanding that the emperor has been poisoned.