While pursuing alien criminals named Bacillus and Geega, Birdy and Tute infiltrate Earth under the cover of a rising Japanese idol and her manager. During one night on a routine mission to apprehend the said criminal, a civilian named Tsutomu Senkawa is used as a human shield. When Birdy realized that she killed him in an accident, she decided that the only way to save his life was to fuse her body with his in order to prevent him from dying. Tsutomu thought that it was all a dream until he found that he was unable to control his body one night after he was supposedly dead.

Bacillus tries to locate and eliminate Birdy, while she, Tsutomu and Tute argue over the constant separate lives that they were trying to hide from the public. Tute gets wounded by Bacillus before he gave Birdy an Elemental Destructor capsule bomb to kill Bacillus and eliminate the threat of him killing an Earth-born civilian in Japan. Birdy mourns Tute's death when he can't heal his wounds from Bacillus' attack.

It has been confirmed: Nakasugi is the host for Ryunka. But Tsutomu wants to protect her, no matter what and so he takes control of Birdy's body when she tried to get close to Ryunka. Nejula knocks them out before their minds fuse completely. When they wake up again, Tsutomu has his own body back and needs glasses again. From now on, Birdy and Tsutomu go separate ways. When Birdy and Nejula arrive at Nakasugi's villa, she is already gone because she went to Tsutomo's place. To protect her from being pursued by her greedy relatives, Tsutomu leaves her in Shymalan's care. After that he discovers Shymalan's true intentions when Nejula confronts him...

Birdy is informed of a break-out from an intergalactic prison, and manages to track down one of the rogue prisoners. Although she is ordered to apprehend the criminals alive, he was killed by the time she arrived on the scene. The only clue is a disguise chip, which dissolved the body.

Nataru and Moss fight but Moss is nearly killed before being rescued by Birdy who attempts to convince Nataru to surrender and receive treatment before his Iksiola state kills him. He refuses and nearly kills Birdy before Senkawa switches in and convinces Nataru that being an Iksiola means more than just killing. Nataru relents and jumps back in time to the moment of the tower attack becoming the man who saves a young Birdy via a time-loop.