"GANTZ:E" is a manga series set in Japan's Edo period, serving as a spin-off of the original "GANTZ" series by Hiroya Oku. The story revolves around a mysterious black sphere known as GANTZ, which recruits individuals who have recently died and forces them to participate in deadly missions against alien creatures. The narrative begins with Hanbei Katou, a skilled swordsman who is killed in a duel. Upon his death, he awakens in a room with other recently deceased individuals, all under the control of GANTZ. The sphere assigns them missions to hunt and eliminate alien targets, offering them a chance to earn points that could potentially grant them freedom or revive a fallen comrade.

The missions are perilous, requiring the participants to utilize advanced weaponry and armor provided by GANTZ, despite their lack of familiarity with such technology. Hanbei, along with his companions, including the resourceful Oka and the determined Natsu, must navigate the brutal challenges while grappling with their own moral dilemmas and the trauma of their deaths. The series explores themes of survival, camaraderie, and the human condition under extreme duress, as the characters are thrust into a relentless cycle of violence and uncertainty.

The Edo period setting adds a unique layer to the story, blending historical elements with the science fiction premise of the original series. The characters' struggles are heightened by their limited understanding of the futuristic tools at their disposal, creating a dynamic tension between their traditional skills and the advanced technology they must wield. As the missions grow increasingly dangerous, the group faces not only external threats from the aliens but also internal conflicts and betrayals, testing their resolve and unity. "GANTZ:E" maintains a fast-paced, action-driven narrative while delving into the psychological and emotional toll of its characters' circumstances.