TV-Series
Description
Tsutomu Senkawa is a high school student whose ordinary life shatters when he is accidentally killed during an interdimensional police operation led by Birdy Cephon Altera. To save him, Birdy merges his consciousness into her own body, forcing them to share one physical form while his original body undergoes reconstruction. He previously required prescription glasses due to poor eyesight, a trait varying across continuities.
His background features a long-standing friendship with Natsumi Hayamiya, who knows intimate details such as a scar on his buttocks and dental issues – knowledge she later uses to verify his identity within Birdy's injury-resistant body. He befriended Ryota Sudou and Kazuyoshi Chigira later and occasionally sought academic help from his older sister, Hazumi Senkawa, who no longer lives with him.
Initially overwhelmed by anxiety and depression, Tsutomu's situation impacts his school performance and social interactions. He fears Birdy and struggles to adapt to their shared existence, sometimes appearing to talk to himself and raising concerns. Over time, he grows braver and more cooperative, recognizing that aiding Birdy's missions protects Earth. He teaches her human etiquette and social norms while assisting investigations using his historical knowledge.
Their personalities gradually assimilate traits: Tsutomu absorbs Birdy's stronger sense of justice and occasional impulsiveness, while Birdy gains some of his empathy. This mutual influence risks merging them into a new entity, potentially erasing both – a central conflict in the *Evolution* manga. In the *Decode* anime, his mind eventually dominates Birdy's body.
Though physically ordinary, Tsutomu accesses Birdy's abilities – superhuman strength, speed, agility, and durability – when she cedes control. During extreme emotional distress, he can forcibly override her transformations, briefly reverting her body to his original form against her will.
His relationship with Sayaka Nakasugi evolves romantically after her recovery from a near-fatal alien weapon accident. He also navigates complex dynamics with the suspicious Natsumi, wary of his behavioral changes.
In the *Evolution* manga, their unstable mental link escalates, threatening one consciousness to permanently subsume the other. Birdy enters a two-year stasis to prevent this, granting Tsutomu full control of her body temporarily.
His background features a long-standing friendship with Natsumi Hayamiya, who knows intimate details such as a scar on his buttocks and dental issues – knowledge she later uses to verify his identity within Birdy's injury-resistant body. He befriended Ryota Sudou and Kazuyoshi Chigira later and occasionally sought academic help from his older sister, Hazumi Senkawa, who no longer lives with him.
Initially overwhelmed by anxiety and depression, Tsutomu's situation impacts his school performance and social interactions. He fears Birdy and struggles to adapt to their shared existence, sometimes appearing to talk to himself and raising concerns. Over time, he grows braver and more cooperative, recognizing that aiding Birdy's missions protects Earth. He teaches her human etiquette and social norms while assisting investigations using his historical knowledge.
Their personalities gradually assimilate traits: Tsutomu absorbs Birdy's stronger sense of justice and occasional impulsiveness, while Birdy gains some of his empathy. This mutual influence risks merging them into a new entity, potentially erasing both – a central conflict in the *Evolution* manga. In the *Decode* anime, his mind eventually dominates Birdy's body.
Though physically ordinary, Tsutomu accesses Birdy's abilities – superhuman strength, speed, agility, and durability – when she cedes control. During extreme emotional distress, he can forcibly override her transformations, briefly reverting her body to his original form against her will.
His relationship with Sayaka Nakasugi evolves romantically after her recovery from a near-fatal alien weapon accident. He also navigates complex dynamics with the suspicious Natsumi, wary of his behavioral changes.
In the *Evolution* manga, their unstable mental link escalates, threatening one consciousness to permanently subsume the other. Birdy enters a two-year stasis to prevent this, granting Tsutomu full control of her body temporarily.