Having a friend that knows you inside out should be a good thing, but in Nishikata's case, the opposite is true. His classmate Takagi loves to tease him on a daily basis, and she uses her extensive knowledge of his behavior to predict exactly how he will react to her teasing, making it nearly impossible for Nishikata to ever make a successful comeback. Despite this, Nishikata vows to someday give Takagi a taste of her own medicine by making her blush out of embarrassment from his teasing. [Written by MAL Rewrite]

Despite their differences in position, three men—the youngest senior executive of the Port Mafia, Osamu Dazai; the lowest ranking member, Sakunosuke Oda; and the intelligence agent, Angou Sakaguchi—gather at the Lupin Bar at the end of the day to relax and take delight in the company of friends. However, one night, Ango disappears. A photograph taken at the bar is all that is left of the three together. Fast forward to the present, and Dazai is now a member of the Armed Detective Agency. The Guild, an American gifted organization, has entered the fray and is intent on taking the Agency's work permit. They must now divide their attention between the two groups, the Guild and the Port Mafia, who oppose their very existence. [Written by MAL Rewrite]

As a child living in the town of Lawless, Angelo Lagusa has witnessed a tragedy: his parents and younger brother have been mercilessly slaughtered by the Vanetti mafia family. Losing everything he holds dear, he leaves both his name and hometown behind, adopting the new identity of Avilio Bruno. Seven years later, Avilio finally has his chance for revenge when he receives a mysterious letter prompting him to return to Lawless. Obliging, he soon encounters the Vanetti don's son, Nero, and seeks to befriend him using the skills he has quietly honed for years. Set during the Prohibition era, 91 Days tells the story of Avilio's dark, bloodstained path to vengeance, as he slowly ends each of the men involved in the killing of his family. [Written by MAL Rewrite]

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.