"Kanzen Oppai Sengen" is a manga series that blends comedy, romance, and slice-of-life elements, centered around the theme of body positivity and self-acceptance. The story revolves around a high school student named Momokawa, who harbors a deep admiration for larger breasts, viewing them as a symbol of beauty and femininity. His fascination leads him to join the school's photography club, where he hopes to capture the essence of what he perceives as perfection.

Momokawa's perspective begins to shift when he meets a classmate named Aoi, a girl with a smaller bust size who is often self-conscious about her appearance. Despite her insecurities, Aoi is confident, kind, and determined, qualities that gradually challenge Momokawa's narrow ideals. As their friendship deepens, Momokawa starts to question his preconceived notions of beauty and learns to appreciate individuality and inner qualities over physical attributes.

The narrative explores the dynamics of their relationship, as well as the interactions with other characters, including members of the photography club and students with varying body types and personalities. Through humorous and heartfelt moments, the series addresses themes of self-esteem, societal beauty standards, and the importance of embracing one's unique traits. The story avoids overtly sexualizing its subject matter, instead focusing on character growth and the development of meaningful connections.

Momokawa's journey from fixation to understanding serves as the central arc, while Aoi's resilience and self-discovery provide a counterbalance, creating a narrative that is both lighthearted and thought-provoking. The manga uses its premise to deliver a message about acceptance and the diversity of beauty, making it a distinctive addition to the genre.