Kachua Pearson, an 11-year-old girl, is one of thirteen human children stranded after hostile alien forces attack their colony on Clayad. She escapes with the others aboard the training combat spacecraft Janous, where they must learn to pilot VIFAM mechas to survive and journey toward Earth.

During the voyage, the group discovers a damaged alien ship piloted by a friendly Astrogater, who reveals Kachua is not human but a Kuktonian—a member of the same species as the hostile Astrogaters. Unaware of her true extraterrestrial origins until this moment, Kachua confronts her identity amid significant tension and distrust from some companions.

Her Kuktonian heritage drives her character development, creating internal conflict as she grapples with loyalty to her human friends and her biological connection to their adversaries. This duality shapes her unique role in the group's dynamics and survival efforts. The narrative explores her struggle to reconcile these identities while contributing to the collective mission despite skepticism.

The OVA "Kachua Kara no Tayori" references her name, and spin-offs or sequels focus solely on her core identity revelation and its immediate impact.