"Magia Record: Puella Magi Madoka Magica Side Story" is a manga adaptation of the mobile game of the same name, set in the universe of the original "Puella Magi Madoka Magica" series. The story takes place in Kamihama City, a location distinct from the original series' setting, where magical girls face unique challenges tied to the city's mysterious properties. The protagonist, Iroha Tamaki, is a magical girl searching for her younger sister, Ui, who has gone missing. Iroha’s journey leads her to Kamihama, where she discovers that the city holds secrets about the nature of magical girls and the system governing their existence.

In Kamihama, Iroha encounters other magical girls, each with their own motivations and struggles. Among them are Yachiyo Nanami, a veteran magical girl who initially appears aloof but becomes a key ally, and Tsuruno Yui, a cheerful and optimistic girl who hides her own insecurities. The group learns that Kamihama is a place where magical girls can escape the tragic fate typically associated with their contracts, as the city’s unique properties prevent Witches—the monstrous entities magical girls must fight—from fully manifesting. Instead, the city is plagued by "Rumors," mysterious phenomena tied to urban legends that magical girls must confront.

As Iroha delves deeper into the mysteries of Kamihama, she uncovers connections between the city, the magical girl system, and her own past. The story explores themes of memory, identity, and the cost of wishes, as Iroha and her companions grapple with the consequences of their choices. The narrative also introduces the Magius, a shadowy organization of magical girls seeking to overthrow the system that binds them, led by figures such as Alina Gray and Touka Satomi. The Magius’s methods and goals create tension among the magical girls, leading to conflicts that test their alliances and resolve.

The manga expands on the lore of the "Puella Magi Madoka Magica" universe, introducing new mechanics and entities, such as the Uwasa, manifestations of Rumors that magical girls must combat. The story maintains the original series’ tone of blending hope and despair, as the characters navigate a world where their wishes come at a steep price. Through its exploration of Kamihama City and its inhabitants, "Magia Record" provides a fresh perspective on the struggles of magical girls while staying true to the themes and emotional depth of the original series.