Seeking the key to the elixir of immortality, the group arrives at the fortress of the island's monstrous ruler, the Tensen. To survive and escape the island, cooperation becomes essential—regardless of whether one is a condemned criminal or an executioner. Meanwhile, the shogunate orders additional landings on the island of the Immortal Realm, led by Shugen Yamada Asayemon. Among them are the Ishigakure clan, who share a past with Gabimaru. Desperate to find the elixir and escape the island, Gabimaru and his companions face the Tensen in a battle that escalates into an all-out confrontation between humans and immortals! (Source: Twin Engine, edited)

Rikuo Nura, a part-youkai and part-human boy, grew up as the young master of the Nura Clan. While he treated the clan, which consists of youkai of all shapes and sizes, like family, he soon learned that he was the only one among his classmates who saw youkai in this light. To most, they were terrifying creatures of folklore who ate children and relished in bloodshed. Taking this to heart, he swore to live his life as a normal human. Normalcy, however, is hard to come by for young Rikuo. Complicating his goal are his youkai attendant, who under the name Tsurara Oikawa, goes to school alongside him; the young onmyouji Yura Keikain; and his close friend Kiyotsugu, who idolizes youkai and hopes to prove their existence. To make matters worse, rival youkai and other entities threaten to harm those Rikuo holds dear. If he wants to protect what's important to him, Rikuo must acknowledge his ancestry—that he is the grandson of the legendary Nurarihyon—and transform at night into a youkai, becoming worthy of being the next leader of the Nura Clan.

Ken Usato, an ordinary high schooler, wishes for something fantastical to occur in his unremarkable life. Such an opportunity arrives when he is transported to another world alongside Kazuki Ryuusen and Suzune Inukami, two prodigious members of his school's student council. Arriving in Llinger Kingdom, the three are deemed to be the heroes tasked with stopping the impending invasion by the Demon Lord's army. However, this is a misunderstanding—Usato was summoned by accident and, unlike his two friends, is not one of the heroes. Despite this disheartening revelation, Usato learns that he has an aptitude for the extremely rare healing magic. This catches the attention of Rose, the intimidating captain of the kingdom's Rescue Team, who forcibly takes custody of Usato to mold him into a full-fledged healer. As he undergoes grueling training under Rose's supervision, Usato resolves to become capable enough to protect his friends from the dangers of this world.

Despite standing at the zenith as the strongest exorcist, Haruyoshi Kuga sought even greater power, which led to his demise at the hands of those who envied his might. As he draws his last breath, he casts a spell that allows him to reincarnate and swears to become more cunning, hoping that all his efforts will prove useful in his next life. Haruyoshi is soon reborn in another world as Seika Lamprogue, an illegitimate son of a noble family that prides itself on magic. However, his new family largely ignores him due to his lineage and magic deficiency. Nevertheless, the unbothered Seika leverages the knowledge from his previous life to make numerous valuable allies. As he begins to explore the true limits of his abilities, Seika must also be wary of the consequences that tarnished his past and avoid repeating the same mistakes.