"The Whole of Humanity Has Gone Yuri Except for Me" is a manga series that explores a world where nearly every individual has developed romantic and sexual attraction exclusively toward members of the same sex, specifically women. This phenomenon, referred to as "yuri," has become the societal norm, leaving the protagonist, a high school student named Haruto, as one of the few remaining individuals who still experiences heterosexual attraction. Haruto's unique orientation places him in an unusual position, as he navigates a world where his feelings are considered abnormal and even stigmatized.

The story begins with Haruto noticing subtle changes in the behavior of those around him, including his classmates and even his family members. Over time, it becomes clear that the shift toward same-sex attraction is not limited to a small group but has become a global phenomenon. Haruto struggles to reconcile his own feelings with the expectations and norms of this new world, often feeling isolated and misunderstood. His attempts to connect with others, particularly women, are met with confusion or rejection, as his heterosexual desires are seen as outdated or irrelevant.

Throughout the series, Haruto interacts with a variety of characters who embody different perspectives on the yuri-dominated society. These include his childhood friend, who has embraced the new norm and is in a same-sex relationship, and a classmate who harbors feelings for Haruto but is conflicted due to societal pressures. The narrative delves into themes of identity, acceptance, and the challenges of living in a world where one's natural inclinations are at odds with the prevailing culture.

As the story progresses, Haruto's journey becomes one of self-discovery and resilience. He grapples with questions of whether to conform to societal expectations or remain true to himself, even if it means facing alienation. The series also explores the broader implications of the yuri phenomenon, including its impact on relationships, family dynamics, and societal structures. By presenting a world where heterosexuality is the exception rather than the rule, the manga offers a thought-provoking examination of how societal norms shape individual experiences and identities.