In the town of Engamori, supernatural beings known as yokai, gods, and humans have been living amongst each other for centuries, each striving to lead ordinary, peaceful lives. One day Buchio, a 20-year-old cat, mysteriously evolves into a nekomata, a feline yokai, near the end of his life. Although this allows him to stay with his human family longer, it also makes him question the reason behind his evolution, along with the special abilities that have recently manifested in himl. Meanwhile, an elementary school girl named Mutsumi Muu-chan Sugimoto begins to feel more attached to Jirou, a tengu—a crow-like yokai—and Jirou begins to fill the void left by her late father. While both are unable to properly communicate their intentions at first, they gradually form a companionship where they protect each other.

Trapped with thousands of people in The New Gate, a virtual reality game, the elite player Shinya Kiritani resolves to clear the game and finally return home. However, after he manages to single-handedly defeat the final boss, Shinya is transported to a new world—seemingly indistinguishable from the one he just escaped. Shinya discovers that as long as the game menu and his skills are unchanged, he cannot leave this oddly familiar world. In his search of a way to break out from this new dimensional prison, Shinya encounters Tiera Lucent, a hotel receptionist who happens to be a protégée of Schnee Raizar—one of Shinya's former party members. With this glimmer of hope, Shinya strives to reunite with Schnee and find out the truth about The New Gate.

Trying to move on in his life, former professional golfer Kazuyoshi Igarashi arrives at Hinoshima Island for a job at its development center. Expecting the island to be a very rural area with nothing much to offer, Kazuyoshi cannot hide his amazement when he discovers a complete golf course made by the island's inhabitants. Using the seaside terrain to their advantage, the people there have adopted golfing as their hobby. To add to his surprise, Kazuyoshi meets a young girl named Tonbo Ooi, who has been playing golf using only a 3-iron—a notoriously difficult-to-use club. As the former pro gets more involved with Tonbo and witnesses her seemingly impossible shots, he begins to see golf in a whole new light, rediscovering how fun the sport can actually be.

After the destruction of their hometown, childhood friends Kafka Hibino and Mina Ashiro make a pact to become officers in the Defense Force—a militarized organization tasked with protecting Japan from colossal monsters known as kaijuu. Decades later, the 32-year-old Kafka has all but given up on his dreams of heroism. Instead, he cleans up the remains of the slaughtered kaijuu after they are defeated by valiant soldiers—including Mina, who has successfully achieved their shared goal. Upon meeting his new coworker, Reno Ichikawa, Kafka faces a mirror of his past self: an ambitious young man whose one desire is to fight as a member of the Defense Force. Unfortunately, the two are soon involved in a freak encounter with a rogue kaijuu. Though Kafka demonstrates his innate heroic nature and rescues Reno from certain doom, he is left gravely injured. While both men recover in a hospital, Kafka is seemingly attacked by another one of the beasts. As a result, he gains the ability to transform into a humanoid kaijuu with the strength and powers of the massive monsters menacing Japan. Dubbed Kaijuu No. 8 by the military, Kafka resolves to use his newfound gifts for the greater good. Tied together by mutual respect, Kafka and Reno set out to join warriors like Mina at the forefront of the Defense Force.