"This Ugly Yet Beautiful World" is a manga series that blends elements of science fiction, romance, and drama. The story centers around Takeru Takemoto, a high school student who works part-time delivering goods, and his friend Ryou Ninomiya. One evening, while on a delivery, they encounter a mysterious glowing light in the forest. From this light emerges a girl named Hikari, who appears to be connected to an otherworldly entity. Shortly after, another girl, Akari, emerges from a similar light and is found by Ryou. Both girls possess extraordinary powers and seem to be linked to a larger, enigmatic force.

As Takeru and Ryou take Hikari and Akari into their care, they discover that the girls are not ordinary humans. Hikari exhibits the ability to transform into a powerful, monstrous form, while Akari displays a deep connection to nature and the environment. The arrival of these girls attracts the attention of a secretive organization, which seeks to capture and study them for their unique abilities. This organization, led by the enigmatic Marii, views Hikari and Akari as potential threats or tools for their own purposes.

The narrative explores the growing relationships between Takeru and Hikari, and Ryou and Akari, as they navigate the challenges posed by the organization and the girls' mysterious origins. Hikari, in particular, struggles with her dual nature, fearing the destructive potential of her monstrous form. Takeru, meanwhile, grapples with his feelings for Hikari and his desire to protect her, even as he questions the true nature of her existence. The story delves into themes of identity, humanity, and the coexistence of beauty and destruction, as the characters confront the implications of the girls' powers and their connection to a larger cosmic event.

As the plot unfolds, it becomes clear that Hikari and Akari are part of a larger phenomenon that could have profound consequences for the world. The series builds toward a climactic confrontation between the protagonists and the forces seeking to control or destroy the girls. Throughout the story, the relationships between the characters evolve, with moments of tenderness and conflict underscoring the central theme of finding beauty in a world that can often seem harsh and unforgiving. The manga concludes with a resolution that ties together the personal struggles of the characters with the broader implications of the events they have experienced.