Birdy Cephon Altera is the protagonist of the anime series 'Tetsuwan Birdy'. She is an intergalactic Federation officer from the planet Alteria, tasked with capturing dangerous criminals that threaten the universe. Known for her extraordinary strength, agility, and combat skills, Birdy is dedicated to maintaining peace and justice. While on Earth, she accidentally merges with a human named Tsutomu Senkawa, leading to a unique coexistence where they must share the same body. This dual existence brings about various challenges and comedic situations as they work together to resolve interstellar threats.