In the aftermath of a great and terrible war, Haruka finds herself the last surviving human on Earth. Though humanity may have been wiped out, she is not entirely alone. Advanced robots have survived the apocalypse, and Haruka lives with five who care for her: Spike, a boyish android who is very attached to her; Trigger, hot-tempered with a penchant for firearms; Cleric, the intelligent problem solver; Reeves, whose thoughtfulness overshadows his intimidating appearance; and Angela, a sword wielding recluse with an aversion towards humans. Residing in a high-rise building at the center of the city, Haruka lives a relatively peaceful life with her mechanical family. However, her life is far from a stable one. Not only is a lack of resources a concern, but violent, remnant robots from the war roam free, ready to destroy whomever they meet. Kurogane Communication follows Haruka as she tries to survive in an apocalyptic world while facing many dangers that will challenge her daily life.

To prepare for reincarnation in another world, Kelvin gives up select memories from his previous life in exchange for powerful abilities, additional skill points, and an S-class summoner title. As a bonus, the goddess facilitating his rebirth, Melfina, offers him a choice of any companion to give him a head start in his summoner role. Kelvin—who has fallen head over heels for Melfina at first sight—promptly chooses the deity, confident that his passionate feelings for her will resurface even without all of his memories. Kelvin embarks on his exciting new journey with Melfina as his guide. However, in order to summon his beloved goddess' physical form, he needs to acquire significant amounts of mana points—and the best way to accomplish this is to level up by fighting strong enemies and making contracts with even stronger companions.

Fourteen-year-old Kouichi Hayase's life has always been a mediocre one, if not dismal. However, those days of being bullied by classmates and escaping to a fantasy of being a hero are put to an end when a certain accident bestows on him a girl and a gigantic humanoid robot called LINEBARREL. The extraordinary power that Kouichi obtains puts him and everything around him on a sudden rollercoaster ride of battles, intrigues and friendship! During the course of his adventure, the boy starts to learn what life has to offer; he meets new friends, bids farewell to the old ones, but most of all he now has considerable responsibilities and is forced to confront the world around him. (Source: Official site)

Half a year after the battle in Okinawa, Excel was looking for a new Mototsumitama to revenge on Reishin. Excel met Mikami and decided to contract with her. Before making the contract, Excel looked back at the encounter with Steiner.