Tetsuwan Birdy Decode

Space Federation officer Birdy Cephon Altera follows an alien fugitive to Earth and adopts the identity of model Shion Arita to get close to her target. Her mission collides with the ordinary life of high school student Tsutomu Senkawa when he accidentally witnesses their confrontation.

A mistake during the fight leaves Tsutomu's body critically damaged, forcing Birdy to preserve his consciousness inside her own body until his can be restored. From then on, they have to share one life: Tsutomu tries to keep up with school and friends while Birdy continues hunting extraterrestrial criminals. As the investigation points toward a far more dangerous conspiracy, keeping their unusual coexistence secret becomes increasingly difficult.