Located in the busiest part of the Eastern Market, Ruyi Inn is a serene retreat that has earned a sacred reputation among the people. Despite its tranquil atmosphere, the inn is protected by three individuals with unique skills: Madame Hong, the shopkeeper; Ren Fansheng, the accountant; and Wu Ren Ai, the cook.

According to this legend, Madam Hong's extraordinary ability to summon the "Flower of Lust" on her forehead and inhale its essence is said to grant her deepest desires. However, the inn's peaceful existence was disrupted by the arrival of A Lan, a skilled assassin from Xianyue Pavilion who has the Purest White Flower within her.