Tetsuo grew up in the chaotic streets of Neo-Tokyo, an orphan raised alongside his best friend, Shōtarō Kaneda. Unlike the confident and charismatic Kaneda, Tetsuo was often perceived as weak and overshadowed by his friend, which bred feelings of insecurity and resentment. This dynamic left Tetsuo yearning for independence and validation, even as he struggled to find his own identity.

Everything changed when Tetsuo’s motorcycle collided with Takashi, one of the psychic children being monitored by the government. This incident awakened Tetsuo’s latent psychic abilities, which rapidly grew beyond his control. Captured by the government for experimentation, Tetsuo’s newfound powers began to twist his mind, turning him into a force of destruction that threatened to annihilate Neo-Tokyo.

Tetsuo’s transformation is reflected in his appearance throughout the story. Initially, he is a thin and wiry teenager with short, dark hair, dressed in the Capsules’ biker gang uniform. As his powers grow, his physical form becomes increasingly grotesque and unstable, culminating in his mutation into a massive, malformed organic mass during the story’s climax. This transformation symbolizes the overwhelming and uncontrollable nature of his psychic abilities.

At the start, Tetsuo is a rebellious and impulsive teenager who craves recognition and respect. He is deeply insecure about being seen as weak, especially in comparison to Kaneda, which fuels his desire for power and independence. However, his lack of maturity and emotional stability makes him ill-equipped to handle the immense psychic power he gains.

As his abilities spiral out of control, Tetsuo becomes increasingly arrogant and destructive, lashing out at those he perceives as threats or obstacles. Despite this, glimpses of his humanity remain, particularly in his relationship with his girlfriend Kaori, highlighting the internal conflict between his original self and the monster he becomes.

• Encounter with Takashi
  Tetsuo’s collision with Takashi sets the events of Akira into motion. The encounter awakens his dormant psychic abilities, leading to his capture and experimentation by the government. This marks the beginning of his transformation from an ordinary teenager into a powerful yet unstable entity.

• Conflict with Kaneda
  Tetsuo’s growing powers and descent into madness place him at odds with Kaneda, his childhood friend and former protector. Their rivalry becomes the emotional core of the story, as Kaneda struggles to stop Tetsuo’s rampage while grappling with the loss of his friend.

• Discovery of Akira
  Obsessed with understanding his powers and surpassing the limitations imposed by the government, Tetsuo seeks out Akira, the source of the psychic energy that destroyed Tokyo decades earlier. This quest leads to the story’s catastrophic climax, as Tetsuo’s unstable powers threaten to unleash another apocalyptic event.

• Final Transformation
  Tetsuo’s psychic abilities ultimately overwhelm him, causing his body to mutate uncontrollably. In his final moments, he is consumed by his powers and transported to another plane of existence by the Espers, leaving Kaneda and Neo-Tokyo behind.