"Air" is a manga adaptation of the visual novel by Key, illustrated by Yukimaru Katsura. The narrative centers on Yukito Kunisaki, a traveling performer who seeks to uncover the legend of the "girl in the sky," a being said to have wings and live in the heavens. Yukito’s journey leads him to a small coastal town, where he encounters Misuzu Kamio, a peculiar and lonely girl who lives with her mother, Haruko. Misuzu exhibits a deep fascination with the sky and often speaks of dreams involving flying, which aligns with Yukito’s quest.

As Yukito becomes involved in Misuzu’s life, he learns about her struggles with a mysterious illness that causes her to collapse frequently. The story delves into themes of loneliness, familial bonds, and the search for meaning, as Yukito’s presence begins to impact Misuzu and those around her. The narrative also explores the lives of other characters, such as Kano Kirishima, a girl who claims to be a descendant of a crow spirit, and her caretaker, Hijiri Kano, who harbors her own secrets. Another key figure is Minagi Tohno, a reserved and stoic girl who works at a local clinic and has a strained relationship with her younger sister, Michiru.

The plot intertwines the past and present, revealing connections between the characters and the legend Yukito is pursuing. Through dreams and memories, the story uncovers the tragic history of a winged girl named Uraha, who was imprisoned and suffered due to her unique nature. This history mirrors the struggles of the present-day characters, particularly Misuzu, whose fate becomes increasingly tied to the legend.

As the narrative progresses, Yukito’s search for the "girl in the sky" takes on a deeper significance, culminating in a poignant exploration of sacrifice, love, and the enduring human desire to transcend limitations. The story’s emotional core lies in its portrayal of the characters’ interconnected lives and their shared longing for freedom and connection, set against the backdrop of a timeless legend.