Birdy The Mighty

After two years of being dormant inside Tsutomu Senkawa, an accidental encounter with their old nemesis violently wakes Birdy up. With Birdy kicking evil's ass once again, the dark secrets of the experiments conducted by the "Agni" corporation are slowly revealed. They seem to be dabbling with human body enhancement, creating what they call "beast men," to combat the alien invasions related to Birdy. (Source: MangaHelpers)

Birdy and Tsutomu are still co-existing in the same body, as Birdy continues her duties as Federation Investigator and celebrity persona, and Tsutomu seeks to balance them with his normal everyday life. When a criminal group connected to the Ryunka incident escape from custody, hiding themselves and their alien identities on Earth, Birdy and Tsutomu are thrown back into action. It seems, however, that there are other forces involved, as well as old faces, which give Birdy time to reflect on the past, and the people that influenced her. (Source: ANN)

While pursuing a criminal, the pretty but reckless interplanetary police officer Birdy Cephon Altera accidentally kills Tsutomu, an Earthling high school student. To make amends, Birdy is forced to share her own body with Tsutomu's spirit so that he can continue his own life. At first, Tsutomu knows nothing about his situation, but he soon discovers that his body is starting to take certain actions without his mind ordering it. In times of action, Birdy takes full control of their shared body, transforming it back into her original female form.