So... is Tetsuwan Birdy Decode finished or not?
NO, it is not finished.
Why?
The anime finished before the manga:
Anime finished: July 22, 2009
Manga finished: August 27, 2012
MangaUpdates contains information about the anime adaptation and indicates that it is incomplete.
Watching Order (by release date)
Here you have all the anime relations we detected ordered by release date, so you can see the reason for this status in context and also use it as watching order.
The mangas and the non-core contents are excluded by default, but you can enable them by clicking the buttons below:
Tetsuwan Birdy Decode
Birdy the Mighty: Decode
Anime - Base
Release date: July 05, 2008
Tetsuwan Birdy Decode:02
Birdy the Mighty: Decode 02
Anime - Sequel
Release date: January 10, 2009
Tetsuwan Birdy Decode: The Cipher
Birdy the Mighty: Decode OVA
Anime - Sequel
Release date: July 22, 2009
Synopsis
Birdy Cephon Altera, a space officer, arrives on Earth to capture a fugitive alien hiding in plain sight. Disguising herself as a human model named Shion Arita, she juggles her secret identity with her mission.
Meanwhile, ordinary high schooler Tsutomu Senkawa gets caught in the crossfire. In a twist of fate, a tragic accident forces Birdy to take drastic measures to save him.
Now, Birdy and Tsutomu must share a single body, leading to a complex and precarious existence. They navigate the challenges of balancing Birdy's dangerous work, Tsutomu's normal life, and Shion Arita's rising career, all while keeping their shared secret safe.