In "Kusuriya no Hitorigoto" Episode 23 titled "Balsam and Woodsorrel," the plot revolves around Maomao challenging Lakan to a series of games and offering a unique bet for each of her victories. If Lakan wins, Maomao agrees to live with him, albeit under the condition that her current employment contract expires first. Maomao's winning condition, on the other hand, is for Lakan to buy the freedom of an aging courtesan from the Verdigris House.

The games between Maomao and Lakan are marked by unusual rules set by Maomao, including a potential challenge to drink poison after each game. Although Maomao loses the initial games, she secures victory by exploiting Lakan's abstinence from alcohol and his inexperience with spirits. This strategic move allows Maomao to dictate the terms for winning.

Simultaneously, Lakan reflects on his peculiar perception of people as chess pieces, a coping mechanism for his inability to recognize faces. This narrative thread ties Lakan's personal history to his encounters with Fengxian, a courtesan, and sheds light on their complex relationship, characterized by mutual respect and intellectual rivalry.

The episode culminates in a revealing moment for Lakan, where he discovers Fengxian's tragic fate, triggered by a failed marriage and the consequences of her subsequent downfall. Lakan grapples with his belated realization and the irreversible impact of his absence on Fengxian's life, evoking a profound sense of loss and regret.

At the end of the episode, Lakan's recollection of the events is interrupted by an interaction with Meimei in the present. This episode sets the stage for further exploration of character dynamics and their consequences in the next episode titled "Jinshi and Maomao."