Humanity and demonkind have been on bad terms for millennia, resulting in the continent of Leunders being split in two. Although the situation has stabilized between the races, the fragile peace breaks when the new demon king launches a fierce all-out attack. With all of the non-demon nations falling to the violence in under a year, humanity's hope rests in a special squad, led by swordsman Kyle Leonard, that must assassinate the demon king in order to bring an end to the war. During the dangerous mission, Kyle ends up in a clash with the demon king that brings him to the brink of death. As Kyle realizes he has lost everything he wanted to protect, a mysterious gem transports him back in time before the conflict even started! Now with knowledge of future events and a strong desire to save his loved ones, Kyle sets out to become even stronger to prevent the extinction of humanity.

Due to frequent misadventures with the supernatural and her hectic school life, Nene Yashiro can barely catch a break until Kamome Academy's annual sleepover event comes around. Nene is excited to blow off some steam with her best friend Aoi Akane and the rest of her class at the get-together. Unbeknownst to her, the sleepover falls on the same date as Urabon, when the line between the dead and the living gets distorted, allowing wicked spirits to come out to the surface. When an evil ghost is about to attack her, Nene is rescued by a mysterious figure: Shinigami, the Sixth Wonder that can trap souls using his flute. In that moment, Shinigami takes notice of Aoi and abducts her to use her as a sacrifice that will close the barrier for good. Joined by Hanako-kun and Akane Aoi, Nene must embark on a journey into the deepest confines of the world of the dead to save her best friend before it is too late.

After getting caught up in an accident, Ryou Mihara is reincarnated in the world of Phi as a water magician. Waking up in a remote forest, he sets out to achieve his ideal slow life by living off monsters and refining his magic. Unbeknownst to Ryou, decades pass without him realizing due to his hidden trait, "Eternal Youth." One day, Ryou stumbles across a shipwrecked adventurer named Abel. As Abel requests Ryou to accompany him to the town of Lune, they embark on a journey through mountains infested with monsters. Upon arriving at the town and registering as an adventurer, Ryou's powerful water magic and equipment are unlike anything anyone has ever seen before. Although his prowess piques the interest of many, Ryou is eager to begin his own adventure and hone his magic even further!

The daily life of high school student Naoto Watari revolves around his little sister Suzushiro. As their parents passed away two years prior, the siblings have been passed from one relative to another, resulting in Naoto taking the most responsibility for her. Although things have not been easy for the two, Naoto is now content with living at their aunt's place. This newfound peace is suddenly turned on its head when Satsuki Tachibana enrolls at Naoto's school. The two used to be good friends, but after Satsuki completely destroyed his family's garden, she disappeared from Naoto's life. Despite what happened, Satsuki seems to be making advances toward Naoto now that they have reconnected. Coupled with other people around him that harbor secrets, Naoto's desire for an idyllic life may be at jeopardy.