Reeling from her recent breakup, Momo Ayase, a popular high schooler, shows kindness to her socially awkward schoolmate, Ken Takakura, by standing up to his bullies. Ken misunderstands her intentions, believing he has made a new friend who shares his obsession with aliens and UFOs. However, Momo's own eccentric occult beliefs lie in the supernatural realm; she thinks aliens do not exist. A rivalry quickly brews as each becomes determined to prove the other wrong. Despite their initial clash over their opposing beliefs, Momo and Ken form an unexpected but intimate friendship, a bond forged in a series of supernatural battles and bizarre encounters with urban legends and paranormal entities. As both develop unique superhuman abilities, they learn to supplement each other's weaknesses, leading them to wonder if their newfound partnership may be about more than just survival.

Grief-stricken over the death of his last family member, his dog Hanako, picture book writer Hotaru Yuuyami suffers from writer's block for nearly two months. Despite his childhood friend and editor Tsubaki Uehara's best efforts, nothing seems to alleviate his pain. But all of this changes one day with the sudden apparition of Kinoko Inu, a mysterious mushroom from his garden that turns into a dog-shaped animal. Much to the great dismay of Tsubaki, Hotaru hastily invites the creature into his abode. Days after Hotaru and Kinoko Inu start living together, the strange mushroom-dog decides to burn the last of Hanako's personal belongings in order to alleviate Hotaru's depression. However, the cohabitation between the overworked writer and his mischievous guest proves more difficult than expected, and Hotaru must let go of his grief if he wants to properly take care of Kinoko Inu.

For blasé college dropout Tsunehiro Sasaki, life has become hopeless. After failing to enter a top university, he has lost all his money trading on financial markets and is now critically indebted. To add to his misery, he learns that he only has at most two years left to live due to an incurable disease. The trajectory of Tsunehiro's life suddenly changes after a group of amateur fishermen saves him from drowning as he was trying to escape from a trio of creditors. While Takaaki Tsutsujimori pushes Tsunehiro to work at the group's workplace—a convenience store that doubles as a fishing shop—Hana Ayukawa tries to share her love for fishing. Although the attempts of the joyful group of anglers initially prove unsuccessful, Takaaki urges Tsunehiro to take a fresh start in life, and the young man eventually accepts the fishing enthusiast's assistance to pay off his debts. As work, friendships, and an unfamiliar hobby all suddenly find their way into his life, Tsunehiro must find the strength to change his ways if he wants to make the best of his remaining time.

For years, the Niflheim Empire and the kingdom of Lucis have been at war. The empire, having dominated most of the world of Eos, covets the power of the last known Crystal, which is held in Lucis' capital city, Insomnia. In order to protect his people from these advancing forces, King Regis Lucis Caelum CXIII used the power of the Crystal to surround Insomnia with a magical wall. Along with this barrier, Regis assembled an elite military task force known as the Kingsglaive. By drawing their power from the king, the Kingsglaive protect Lucis' borders from the onslaught of the empire and other forces that would do them harm. One such member of the Kingsglaive is Nyx, a man nicknamed "The Hero" by his fellow warriors due to his arrogance and desire to save everyone. However, his pride gets the better of him, causing him to disobey his captain's orders, resulting in a demotion. Now, Nyx spends his days guarding the city gates, but things begin to change once word gets out that Regis plans to sign a peace treaty with their sworn enemies.