"This Ugly Yet Beautiful World" is a 12-episode anime 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 with his friend Ryou Ninomiya. One evening, while riding their scooter through the forest, they encounter a mysterious glowing light. From this light emerges a girl named Hikari, who appears to have no memory of her origins. Takeru feels an inexplicable connection to her and decides to take her under his care.

As Takeru and Ryou integrate Hikari into their lives, another girl named Akari emerges from a similar light. Akari is found by Mari, a classmate of Takeru and Ryou, and she too exhibits strange, otherworldly qualities. Both Hikari and Akari possess extraordinary powers, including the ability to transform into powerful, otherworldly beings. These transformations are triggered by intense emotions, particularly when they feel threatened or vulnerable. The girls' presence attracts the attention of a secretive organization that seeks to study and control them, believing them to be connected to an impending global catastrophe.

The narrative explores the growing relationships between the characters, particularly the bond between Takeru and Hikari, which deepens as they uncover more about her true nature. Hikari's existence is tied to a larger cosmic event, and her presence on Earth is part of a cycle that could lead to the planet's destruction. As the story progresses, it becomes clear that Hikari and Akari are not ordinary humans but entities with a purpose tied to the fate of the world. The series delves into themes of love, sacrifice, and the duality of beauty and destruction, as the characters grapple with their roles in the unfolding events.

The main characters include Takeru Takemoto, a kind-hearted but somewhat aimless teenager who becomes Hikari's protector; Hikari, the enigmatic girl with a mysterious connection to Takeru; Ryou Ninomiya, Takeru's best friend, who provides comic relief but also harbors deeper feelings for Mari; Mari Shidou, a responsible and caring classmate who takes Akari under her wing; and Akari, the second mysterious girl who forms a close bond with Mari. The series balances moments of lightheartedness with darker, more introspective scenes, creating a narrative that oscillates between the mundane and the extraordinary.

As the story reaches its climax, the characters are forced to confront the reality of Hikari and Akari's origins and the inevitable consequences of their presence on Earth. The series concludes with a resolution that ties together the emotional and thematic threads, leaving a lasting impression on the viewer. The interplay between the characters' personal struggles and the larger, existential threat they face forms the core of the narrative, making "This Ugly Yet Beautiful World" a compelling exploration of human emotions and cosmic destiny.