Kouji Maeda is an 18-year-old high school student standing 173cm tall. His hobbies include relaxing, indulging in laziness, and showing interest in girls. He becomes the protagonist of a narrative centered on his part-time job at the Pia Carrot restaurant chain.

The story begins when Kouji seeks employment at Pia Carrot after spotting a girl in the restaurant's uniform, sparking his curiosity. While daydreaming about the summer job, he collides with Azusa Hinomori, creating a significant misunderstanding that ignites instant, intense mutual dislike.

Despite clashing with Azusa and arriving late due to the incident, Kouji displays remarkable persistence to secure a waiter position at Pia Carrot, ultimately succeeding. A pivotal moment occurs when he learns Azusa has been hired at the same location, forcing them into daily coworker interactions. Their proximity challenges the initial animosity. Through constant exposure in the workplace, their relationship shifts—feelings of hate gradually transform, revealing deeper, more complex emotions beneath the surface conflict.

Kouji Maeda later appears as a supporting character in Welcome to Pia Carrot 3, maintaining his presence within the franchise's continuity.