The story follows the two titular girls Escha and Chron, whose contrasting personalities are like the sun and moon. The two girls are from Terminal, a future post-apocalyptic world that's empty and monochrome. The two girls cross worlds and arrive in the present day, which they call Transit. As Escha and Chron experience the light (scenery) and sound (music) of the real world, the future world of Terminal gradually changes into a more vivid world. (Source: ANN)

Tennomifune Academy is an elite institution for the best and the brightest, with the exception of Class 1-7, the so-called "Happiness Class." Each member of the classroom copes with personal misfortunes, and the special class is geared to help them move past their issues and find true happiness. After being accepted into the academy, An Hanakoizumi, Ruri Hibarigaoka, and Botan Kumegawa find themselves placed into the Happiness Class, plagued by dreadful luck, love problems, and bad health respectively. Alongside their classmates, they do their best to overcome the difficulties they are faced with in pursuit of a life filled with joy. [Written by MAL Rewrite]

Ritsuka Tachibana has always been a good student, so she is completely shocked when she is suddenly summoned by the student council. Even more, they seem to think of Ritsuka as a troublemaker. Led by the handsome Rem Kaginuki, the student council—also consisting of Urie Sogami, Shiki Natsumizaka and Mage Nanashiro—tries to question her, but it soon becomes clear that they have ulterior motives. However, this is only the beginning. When her mother gets kidnapped, her life is turned upside down, and Ritsuka gets drawn into a world of vampires and devils. Both groups are searching for the "Grimoire," a forbidden item allowing its owner to rule the world. The return of her brother Lindo from overseas gives her hope, but even he appears to be hiding something. In a world filled with secrets, Ritsuka questions whom she can trust in this dark musical tale, while the handsome and dangerous members of the student council compete for her attention. [Written by MAL Rewrite]

Ichirou Suzuki, a programmer nearing his thirties, is drowning in work. Worn out, he eventually has a chance to catch up on sleep, only to wake up and discover himself in a fantasy RPG world, which is mashed together from the games he was debugging in reality. In this new place, he realizes that not only has his appearance changed to a younger version of himself, but his name has also changed to Satou, a nickname he used while running beta tests on games. However, before Satou can fully grasp his situation, an army of lizardmen launch an assault on him. Forced to cast a powerful spell in retaliation, Satou wipes them out completely and his level is boosted to 310, effectively maximizing his stats. Now, as a high-leveled adventurer armed with a plethora of skills and no way to return to reality, Satou sets out to explore this magical new world. [Written by MAL Rewrite]