Shinobu Oomiya once left Japan to participate in a homestay in England. During her time there, she became close friends with Alice Cartelet, the daughter of the family she was living with. However, when it was time for Shinobu to return to Japan, the two were able to express their sorrow despite the language barrier between them. Five years later, now a first year student in high school, Shinobu receives a letter by air mail in a language she does not understand. This letter is penned by none other than Alice, detailing her own homestay in Japan. In fact, Alice will be attending Shinobu's high school and living with her! Alongside their friends Youko Inokuma, Aya Komichi, and Karen Kujou, the five girls attend school together and learn about what their different cultures have to offer, day after day. [Written by MAL Rewrite]

Human civilization no longer revolves around fire, but is instead now driven by fear of it. Repeated wars have changed human biology, and people now spontaneously combust when they get close to natural flame. However, a new source of energy prevents society from complete collapse: a stone-shaped material used to produce light and steam lies within the bodies of monsters that infest numerous forests. Those tasked with collecting this precious resource are called fire hunters. Touko, a young village girl, is saved from a forest monster by a fire hunter who perishes during his heroic action. After the hunter's dog, Kanata, heals from his own injury, the girl's family sends her to the capital in order to return Kanata and the hunter's fire sickle to his relatives. Elsewhere, the fire hunter's son, Koushi, and his sister are adopted by a wealthy family. Koushi learns some troubling facts related to the country's ruling royal family. He conducts secret research on a special fire stone found by his late father, kickstarting a race against time between the country's leaders and those trying to save mankind from its ultimate demise.

The Bladebreakers have to join forces once again because a mysterious group under the lead of Oozuma has defeated them, but the real enemy is not Oozuma. The real threath is formed by a group of people who use cyber-BitBeasts to capture the original ones from the Bladebreakers. (Source: ANN)

The story revolves around Maya, the daughter of the former Headmaster of Waldstein Academy, and a time traveling agent Fumiaki Uchida. In the year 2012, the world had been invaded by aliens and time travelers were sent back to the year 1999 in order to find and destroy the Nostradamus Key, which Nostradamus Prophecy foretold as what would bring about the apocalypse. The series then turns to the year 1999, where Maya returns to the Academy with the intention of destroying the Academy by superseding her late father's position as the principal. Her plan was interrupted when she meets Fumiaki and learns of the forthcoming destruction. Despite being distrusting towards Fumiaki, they form a pact to look for the Nostradamus Key. In order to find the Nostradamus Key, time agents were provided with specially created cell phones. When a user finds an object of interest, by thinking of destroying it and taking a photo, and if the resulting image is that of a peaceful world, then the subject is the Nostradamus Key. Conversely, if the subject is not the Nostradamus Key, then the photo displays destruction. By using the phone, Maya and Fumiaki investigates occult occurrences as they occur in the town. (Source: Wikipedia)