"Air In Summer" is a two-episode OVA that serves as a side story to the main "Air" series, expanding on the backstory of Kanna, a central figure in the overarching narrative. Set in a distant past, the story revolves around Kanna, a winged girl with mysterious powers, and her journey alongside her loyal companion, Ryuya. Kanna is pursued by soldiers and priests who seek to exploit her abilities, believing her to be a divine being capable of granting immortality. Despite her powers, Kanna is portrayed as a vulnerable and lonely figure, longing for a place where she truly belongs.

Ryuya, a wandering swordsman, becomes Kanna's protector and guide. Their relationship is central to the narrative, as Ryuya vows to help Kanna find her mother, whom she believes resides in a distant land. The duo travels across a desolate and war-torn landscape, facing numerous challenges, including hostile forces and the harsh realities of their world. Along the way, they encounter a village where Kanna's presence brings both hope and conflict, as the villagers grapple with their own beliefs and fears about her divine nature.

The OVA delves into themes of sacrifice, loyalty, and the search for belonging. Kanna's journey is marked by moments of both joy and sorrow, as she struggles to reconcile her identity with the expectations placed upon her. The story also explores the bond between Kanna and Ryuya, highlighting their mutual dependence and the sacrifices they make for one another. The narrative maintains a poignant and melancholic tone, reflecting the tragic undertones of Kanna's existence and the inevitability of her fate.

"Air In Summer" provides essential context for the main "Air" series, offering a deeper understanding of Kanna's origins and the emotional weight of her story. The OVA's concise yet impactful storytelling complements the broader narrative, making it a significant addition to the "Air" universe.