"Co-Ed Affairs" is a romantic comedy anime that explores the dynamics of relationships and misunderstandings in a co-educational high school setting. The narrative centers around a group of students navigating the complexities of adolescence, friendship, and romance. The protagonist, a reserved and academically focused male student, finds himself entangled in a series of humorous and heartfelt situations after being paired with a lively, outgoing female classmate for a school project. Their contrasting personalities create a blend of comedic tension and gradual mutual understanding.

The plot unfolds through a series of episodic encounters, each highlighting different aspects of teenage life, from school festivals and club activities to exam stress and social pressures. Secondary characters, including a mischievous best friend, a strict but caring teacher, and a rival love interest, add depth to the story, creating a web of interconnected relationships. The series balances lighthearted moments with more poignant scenes, addressing themes such as self-discovery, the importance of communication, and the challenges of balancing personal aspirations with social expectations.

As the story progresses, the protagonist and his classmates confront their insecurities and learn to navigate their feelings, leading to moments of growth and reconciliation. The anime avoids overly dramatic tropes, instead focusing on relatable, everyday scenarios that resonate with its audience. By the conclusion, the characters have developed stronger bonds, and the central relationship evolves into a meaningful connection, leaving room for reflection on the journey they have shared. The series captures the essence of youthful experiences, blending humor, emotion, and a touch of nostalgia.