Akiyoshi Okazaki is a minor but memorable character from the Tokyo Gantz team, introduced during the mission at the Buddhist temple. Before his death and subsequent transfer to the Gantz room, Okazaki lived as a hikikomori, a reclusive individual who spent almost all his time indoors. His daily life was consumed by playing violent video games and army-themed eroge, eating junk food, and collecting army loli figures. His death was not heroic or dramatic; he choked to death on his own food while absorbed in a video game.

Okazaki's personality is largely defined by the isolating lifestyle he led. Upon arriving in the Gantz room, he initially appears defensive and fearful, sitting on the ground in a protective posture. He is quick to join in the praying led by the self-proclaimed leader Muso Tokugawa, suggesting a desperate need for guidance or protection. However, his true nature begins to show once the mission starts and he gets his hands on a weapon. He eagerly grabs an X-shotgun and ignores attempts to organize a group prayer, more interested in examining his new firearm.

His motivations are simple and primal. Trapped in a deadly game for the first time, Okazaki is driven by a newfound sense of power. After watching more aggressive players like Kei Kurono and Juzo Togo fight the aliens, he becomes emboldened. He is shown cheering for Kurono and then actively hunting the smaller Buddhist temple aliens. In a particularly disturbing moment, he shoots a wounded alien that is seemingly begging for its life, remarking on how powerful he feels. This act reveals that his years of playing violent video games have blurred the lines between virtual and real violence, and he relishes the opportunity to exert power over a helpless foe, treating the alien's death throes as an extension of his games.

Okazaki's role in the story is that of a cautionary example. He represents a type of person who is transformed by the Gantz mission's environment of unchecked violence. Unlike Kei Kurono or Masaru Kato, who grapple with the morality of their actions, Okazaki quickly abandons any restraint. His primary relationship is not with any other character but with the weapons and the act of killing itself. He tries to engage Juzo Togo by asking if he likes guns, but is ignored, showing his social awkwardness even in this extreme situation. He briefly idolizes Kei Kurono for his power, viewing him as a figure to emulate rather than a person.

His development is extremely short but brutal. He goes from a cowering outsider to an eager, sadistic participant in a matter of minutes. This trajectory is abruptly and violently cut short. When he charges at the colossal Daibutsu alien, his overconfidence proves fatal. The alien effortlessly picks him up, and as Okazaki screams for help and protests that he does not want to die, the creature bites off his head and eats his body in three pieces. His death is a stark reminder that the power he felt was an illusion.

In terms of abilities, Okazaki demonstrates no physical prowess or strategic thinking. His only notable skill is his handling of the X-shotgun, showing he is proficient with the weapon, likely due to his extensive experience with video game simulations. He dual-wields two X-shotguns with a degree of comfort, which is more than most first-time participants can manage. However, this technical familiarity with a fictional weapon does not translate into real combat survival skills, as his reckless charge directly into the mouth of the Daibutsu alien clearly demonstrates.