"Jinki: Extend" is a science fiction manga series set in a world where humanity faces threats from mysterious mechanical beings known as Moribito. The narrative intertwines the lives of individuals connected to the development and operation of Jinki, humanoid mecha designed to combat these threats. The story primarily revolves around Aoba Tsuzaki, a young girl with a passion for building models, who is unexpectedly drawn into the world of Jinki after being kidnapped and taken to a secret underground base in Venezuela. There, she encounters Shizuka Tsuzaki, her grandmother and the leader of the organization ANGEL, which is dedicated to fighting the Moribito.

Aoba’s journey involves her adaptation to the high-stakes environment of piloting Jinki, as well as her interactions with other key characters, including Ryohei Ogawa, a skilled Jinki pilot with a mysterious past, and Genta Morii, a scientist deeply involved in the development of the mecha. The narrative explores themes of family, identity, and the ethical implications of advanced technology, as Aoba uncovers secrets about her own lineage and the true nature of the Moribito. The story also delves into the personal struggles and motivations of the characters, particularly their relationships with one another and their roles within the larger conflict.

As the plot progresses, the focus shifts between Aoba’s growth as a pilot and the broader efforts of ANGEL to protect humanity. The series balances action-packed mecha battles with character-driven drama, revealing layers of intrigue surrounding the origins of the Moribito and the purpose of the Jinki. The narrative builds toward a climactic confrontation that tests the resolve and abilities of the protagonists, while also addressing the moral dilemmas inherent in their fight. Through its exploration of human resilience and the consequences of technological advancement, "Jinki: Extend" presents a compelling blend of science fiction and personal storytelling.