Seto is an ordinary and uninteresting high school student who is frequently harassed by his classmate Anjou, a troublemaker whose motives are unknown. Despite their contrasting personalities, with Seto being more reserved and Anjou being more lively, Anjou enjoys taunting and tormenting Seto. Seto struggles to cope with Anjou's behavior and fails to realize that his entertaining reactions are why she enjoys tormenting him. Yancha Gal no Anjou-san chronicles the amusing daily interactions between these two polar opposites as their playful teasing evolves into a cherished companionship. However, it remains unclear whether Anjou's flirtatious banter with Seto is genuine or not.