The world is in the midst of the industrial revolution when horrific creatures emerge from a mysterious virus, ripping through the flesh of humans to sate their never-ending appetite. The only way to kill these beings, known as "Kabane," is by destroying their steel-coated hearts. However, if bitten by one of these monsters, the victim is doomed to a fate worse than death, as the fallen rise once more to join the ranks of their fellow undead. Only the most fortified of civilizations have survived this turmoil, as is the case with the island of Hinomoto, where mankind has created a massive wall to protect themselves from the endless hordes of Kabane. The only way into these giant fortresses is via heavily-armored trains, which are serviced and built by young men such as Ikoma. Having created a deadly weapon that he believes will easily pierce through the hearts of Kabane, Ikoma eagerly awaits the day when he will be able to fight using his new invention. Little does he know, however, that his chance will come much sooner than he expected... [Written by MAL Rewrite]

After an enthusiastic invitation from her friend, Kaede Honjou reluctantly agrees to try New World Online: a very popular VRMMO played by thousands of people across Japan. Naming her in-game character Maple, she sets out on her journey. As a complete novice to such games, she allocates all of her stat points into vitality, desiring to not get hurt. With not a single point in any other stat, Maple has extraordinarily high defense, but she can't move quickly or hit hard. This doesn't end badly for her, however. Due to her high defense, Maple acquires overpowered skills such as Total Defense, Poison Immunity, and Devour. These skills, along with the incredibly powerful items she obtains, allow her to obliterate most enemies in a single hit. After only a few days of playing the game, Maple claims third place in a server-wide event, gaining a reputation as a player who is both unkillable and absurdly powerful. Despite her overpowered character, Kaede has much to learn. As she progresses through the game, she meets new friends and acquaintances, helping her complete new levels and events. Through all of her adventures, she may even pick up some other crazy skills that exceed all expectations. [Written by MAL Rewrite]

The original episode will serve as a bridge between the second and third season.

Twenty-two-year-old Eikichi Onizuka—ex-biker gang leader, conqueror of Shonan, and virgin—has a dream: to become the greatest high school teacher in all of Japan. This isn't because of a passion for teaching, but because he wants a loving teenage wife when he's old and gray. Still, for a perverted, greedy, and lazy delinquent, there is more to Onizuka than meets the eye. So when he lands a job as the homeroom teacher of the Class 3-4 at the prestigious Holy Forest Academy—despite suplexing the Vice Principal—all of his talents are put to the test, as this class is particularly infamous. Due to their utter contempt for all teachers, the class' students use psychological warfare to mentally break any new homeroom teacher they get, forcing them to quit and leave school. However, Onizuka isn't your average teacher, and he's ready for any challenge in his way. Bullying, suicide, and sexual harassment are just a few of the issues his students face daily. By tackling the roots of their problems, Onizuka supports them with his unpredictable and unconventional methods—even if it means jumping off a building to save a suicidal child. Thanks to his eccentric charm and fun-loving nature, Class 3-4 slowly learns just how enjoyable school can be when you're the pupils of the Great Teacher Onizuka. [Written by MAL Rewrite]