Birdy The Mighty: Decode 1

Birdy is an interstellar space agent sent to Earth to investigate the appearance of aliens under the secret identity of a popular Idol. A frantic late night mission causes her to catch an innocent schoolboy in her deadly line of fire. Thanks to a special space technology, Birdy knows a way to restore his life by joining their two bodies into one. Now Tsutomu and Birdy must share the same body, mind and adventures while his broken flesh slowly heals.