During the pursuit of a criminal, Birdy Cephon Altirra, a reckless but beautiful interplanetary police officer, unintentionally causes the death of Tsutomu, a high school student from Earth. As an act of reparation, Birdy is compelled to coexist with Tsutomu's spirit within her own body, allowing him to resume his life. Initially, Tsutomu is unaware of the arrangement, but soon realizes that his body is initiating actions without his command. During moments of action, Birdy takes the lead and transforms their joint body back into her original female form.
