Plot
Fire Punch takes place on an Earth that has become frozen over and barren, purportedly at the hands of a being known as the Ice Witch. The witch is among a few who possess special abilities known as "blessings". The protagonist, Agni has the blessing of regeneration, along with his sister Luna. They help the few elders in the village subsist on the meat of Agni's severed arms. One day, their village is visited by a blessed named Doma who offers to take Agni to his city of Behemdorg. Doma, disgusted at their practice of cannibalism, immolates the inhabitants with his inextinguishable flames. Luna, whose regeneration is slower, also succumbs, but not before imploring Agni to "live".
Constantly on fire, Agni's body breaks down and regenerates, leaving him in anguish. Over eight years, he is able to control his body again, vowing to get revenge on Doma. Agni comes across a convoy of slaves to Behemdorg and kills the soldiers. A boy named Sun (blessed with the power to generate electricity), who thinks Agni is a god, follows him. Later, more soldiers find Agni, and one of them, Judah, a blessed resembling Luna, beheads him. They take him to Behemdorg, and Sun is tied up and made to generate power for the city. A repentant Doma asks Agni for forgiveness, but does not allow Agni to kill him.
Judah decides to try to kill the seemingly immortal Agni by throwing his severed head into the ocean, taking a train there. Also on the train is Togata, another regenerative blessed, and twisted cinephile who has taken an interest in Agni, aiming to make him the subject of a film as director. Togata kills all the Behemdorg soldiers on the train, saving a girl named Neneto from being raped and making her camerawoman. Agni agrees to let Togata film his revenge on Doma in exchange for training.
At Behemdorg, Agni decides to free the slaves. While fighting Behemdorg's blessed, Agni's flames burn the city down, killing the residents. Agni defeats the blessed and the slaves are transported by an ally, who also views Agni as a god they come to call 'Fire Punch'. Judah, no longer needing to maintain a facade of divine revelation, sets herself on fire using Agni's flames, but is stopped when the Ice Witch beheads her. The Ice Witch reveals she is a fan of Agni and disappears, taking Judah's severed head with her.
The freed slaves of Behemdorg (including Sun) arrive at an abandoned village, and are soon joined by Togata and Agni. Togata tells Agni that in order for the village to survive, they will need to eat meat carved from Agni's body, and that the villagers will worship him as their god. One of Agni's disciples informs him that soldiers of Behemdorg have been found nearby, and that Doma is among them. The disciple, a blessed with a limited telepathic ability, also reveals that Togata is transmasculine.
Elsewhere, the Ice Witch nurses Judah back through her regeneration, and reveals that the two of them are 'evolved' - members of an advanced form of humanity who all share a genetically-identical appearance, and have all the abilities of every blessed. The Ice Witch, actually named Surya, says that the rest of the evolved migrated away from Earth during the Ice Age, and that she intends to warm the planet again by transforming Judah into a large tree which will absorb the life energy of every living thing, thereby starting a new epoch. Surya's stated reason for doing so is that she believes allowing the planet to reset will eventually create another civilization that will produce a Star Wars film that was cancelled during production many years prior.
Meanwhile, Agni calms Togata down, as they had been planning to abandon him after their secret was revealed. The two reconcile and Agni declares he is going to confront Doma, which Togata is eager to record for their film. They find Doma, now caring for a number of children, and after a brief conversation, Agni resolves not to kill him so as to end the cycle of vengeance. However, he is overcome by his memories of Luna's death, and ends up killing Doma and many of the children in a fugue state, recorded by Togata. Upon awakening, Agni tries to kill himself by walking into a lake; Togata drags him out, but catches on fire in the process and dies.
Carrying Togata's body, Agni discovers a large tree has overcome the village. The tree is Judah, transformed by the Ice Witch. Agni hears the voice of Judah, which he believes to be Luna, imploring him to kill her within the tree. He is able to destroy the tree, and in the process Judah uses her evolved powers to extinguish Agni's flames and halt his regeneration. When Judah regenerates, she has lost all memory of who she is, and Agni gives her the name Luna and tells her he is her older brother.
Agni and Luna leave to find shelter, and find an abandoned salt mine, where they loot some clothes. The pair are apprehended by Lean, a member of a small group of survivors from Doma's group of children, including Doma's pregnant daughter, Ranu. Agni and Luna stay there for a decade, while Agni steadily recovers his regenerative abilities. As Agni only introduces himself as 'brother', none of the others know he is the 'Fire Punch' responsible for Doma's death. During this time, Agni and Luna begin a sexual relationship.
In the village, Sun has risen to a messianic position amongst the followers of Agni's religion, Agnism. He is aware of Agni's incognito existence at the salt mine but chooses to leave them be, until he discovers that the Luna with whom Agni is living is the Judah responsible for some of the atrocities at Behemdorg. He orders her capture, at the behest of the Ice Witch, who still wishes to complete the tree ritual. When Luna is captured, Sun declares his intent to burn her alive, and executes the Ice Witch when she protests. Agni deliberately ignites himself again and surrenders to his single-minded 'Fire Punch' alter ego, pursuing the Agnists to rescue Luna. Sun is elated to see Agni, though the latter does not recognise him at all.
The two fight one another, resulting in Sun burning to death. Luna, having recovered some of her previous memories, destroys half of Agni's brain, allowing him to regenerate with no memories as she had done previously. She then entrusts the care of the amnesiac Agni to Neneto, before allowing herself to complete the tree ritual to thaw the planet.
After eighty years pass, a small community lives in warm, fertile land around the base of Luna's tree, which branches far into the stars to draw energy from distant planets. Agni - now renamed Sun - passes time in an empty cinema, though there are no films to show. He is summoned to Neneto's bedside as she dies. One of her subordinates passes on a pill which will allow him to commit suicide without regenerating, and urges him to use it as the surviving people on earth have discovered weapons capable of killing all remaining life. They also pass on Togata's camera, though - due to file corruption - the footage recorded on it has no sound and is entirely in black and white. Sun watches the footage of his own life as Agni, and although he does not recognise the people or events, clenches his fist as he watches.
Hundreds of years later, Luna remains in the tree as the branches spread out to ever more distant stars. Millennia pass, and she wonders to herself if she will be trapped there forever. She watches the Earth below her destroyed by an asteroid. Millions of years later, when the universe is now dead, Sun joins her there, and although they do not remember each other, they embrace and then fall asleep.
The last panel shows two people resembling Agni and Luna leaving an empty cinema.
