Shinjuku, 1983. A member of the Kaeda Yakuza gang, Akutsu Jouji, has lost in a brawl with a university cheering squad, and begs for forgiveness through bitter tears. Since then, nothing has gone well in Jouji's life, until 10 years later in 1993, his friend was ordered to kill him, and as he ran away he killed himself, ending his miserable life. But when Jouji opened his eyes, he was in Shinjuku in 1983, at the fight with the university students that caused things to go wrong. Now with ten more years of memories and experience, Jouji repels the university students with spirit and wisdom. Now he swears to wear a gold emblem around town, and begins his life anew. (Source: Hokuto no Gun)

Having been accepted into the Kaede Inn, Nana struggles to find some way to contribute, though she inadvertently brings more trouble than assistance. However, Nana's worries are directed more towards fellow resident Nyu, whom she had only known as Lucy, the violent Diclonius. Fearful that Nyu will unleash the same horrific savagery—violence that scars Nana to this day—upon those close to her, Nana faces a dilemma: attempt to live peacefully alongside Lucy with all the uncertainty that that entails or dispose of the source of her worries, shattering the relationships she has formed at the inn. As Nana struggles to come to a decision, Nyu recalls a painful memory of one of her dearest friends and one of her greatest rivals.

The Equipment: Living Forms, or ELFs, were created over fifty thousand years ago to assist humankind in their combat against the Honkai—the decay. With the project's success, the ELFs soon became sentient, compelling humanity to treat them as near-equals. However, when the Ninth Herrscher laid waste to the planet, almost all traces of ELFs vanished into the Sea of Quanta's endless abyss. Yet, there seems to be a bubble universe where the ELFs' fate has taken a brighter turn. Here, they live peacefully among humans and attend a specialized institution, ELF Academy, where they study as if they were human beings themselves. From Selune's Elegy's chuunibyou tendencies to Blood Embrace's gangster shenanigans, the peaceful environment of the academy is guaranteed to provide relief from the depressing state of the main universe.

Spontaneous Human Combustion: a chaotic phenomenon that has plagued humanity for years, randomly transforming ordinary people into flaming, violent creatures known as Infernals. While Infernals make up the first-generation accounts of Human Combustion, the second and third generations became known as pyrokinetics—people gifted with the ability to manipulate and control their flames while remaining human. To combat the Infernal threat and discover the cause, the Tokyo Armed Forces, Fire Defense Agency, and Holy Church of Sol produced their answer: the Special Fire Force. Young and eager third-generation pyrokinetic Shinra Kusakabe, nicknamed Devil's Footprints for his explosive ability to ignite his feet at will, becomes a member of the lively Special Fire Force Company 8. Upholding the brigade's duty to extinguish the blazing Infernals and lay their souls to rest, Shinra is determined to become a hero who will save the lives of those threatened by the flame terror. However, this is not the hero's game Shinra imagined. The Fire Force is a fractured mess of feuding brigades, abnormal Infernal sightings are increasing all over Tokyo, and a shadowy group is claiming to have answers to the strange fire that caused the death of Shinra's family 12 years ago. Faced with many obstacles within and outside the Fire Force, Shinra fights to uncover the truth behind the burning mysteries that have kept him in the dark.