Just an ordinary teenager, Kobeni Yonomori receives quite the surprise on her 16th birthday—a fiancé and a sister-in-law she never even knew she had. As a result of an arrangement that her late grandfather made, Hakuya Mitsumine and his younger sister Mashiro have moved from their countryside home to the Yonomori household in order to deepen their relationship with their new family members. Mikakunin de Shinkoukei follows Kobeni's love life with Hakuya as she tries her best to adjust to the abrupt changes forced upon her. However, as some extraordinary secrets regarding the siblings come to light, Kobeni will find her life changed forever.

Shun Asanaga is a 15-year-old junior high school student with an optimistic and bright personality. One day, he finds a mysterious crystal in the office of his father, who is a scientist and businessman. When Shun touches it, the world becomes distorted, and he is sent into the world of Endra. Emilio, a prince of the kingdom of Endra, is nearing his 16th birthday and despises the reigning king, Delzain. Since Emilio is now at the age when he can inherit the throne, he takes up a weapon and attempts revenge. However, because Emilio is too weak, he is captured by Delzain and put in prison. When Emilio is in grief, the wall of his cell becomes distorted and Shun appears from there with two goals: return to his own world, and complete Emilio's revenge. What future lies ahead for the two boys trying to survive in Endra, yet raised in two different worlds? (Source: MAL News)

Every 60 years, the heavens conduct a sacred ritual called ETM12. This custom involves selecting worthy Eto-musume—celestial beings representing different animals—to become one of the members of the Chinese zodiac, or Eto-shin. However, since the first ETM12 two thousand years ago, the original batch of Eto-shin reigns with no one being able to replace them. Nyaa-tan is a cat Eto-musume who aspires to become a member of the zodiac in the ongoing ETM12. Fulfilling her ambition requires her to secure 12 seals, one for each Eto-shin. To that end, she must win various types of battles using Sol/Lull—divine energy created by people's positive emotions. This task is not easy however, as her powers as an Eto-musume are far below the abilities of a single Eto-shin. As such, she needs a constant source of energy. But in a chance encounter, Nyaa-tan meets Takeru Amato, a man who has just transferred to the apartment where she is secretly staying. To Nyaa-tan's delight, Takeru discovers that he gives out high quality Sol/Lull—something that sets him apart from most people. With this, the story of Takeru and Nyaa-tan begins. As Takeru supports Nyaa-tan in her dreams, he meets the Eto-shin and begins to uncover a mysterious past.

After his confrontation in the Nether with his younger brother Shou, Shinra Kusakabe's resolve to become a hero that saves lives from the flame terror strengthens. Finding a way to turn the Infernals back into people, unraveling the mystery of the Evangelist and Adolla Burst, and saving his mother and Shou—these are the goals Shinra has in mind. However, he has come to realize that attaining these goals will not be easy, especially with the imminent danger the Evangelist poses. The Evangelist's plan is clear: to gather the eight pillars—the individuals who possess Adolla Burst—and sacrifice them to recreate the Great Cataclysm from 250 years ago. Having been revealed by the First Pillar that the birth of a new pillar is approaching, Shinra is determined to protect his fellow pillars from the Evangelist. Thus, the fiery battle between the Special Fire Force and the Evangelist ignites. Together with the Special Fire Force, Shinra's fight continues as he uncovers the truth about the Great Cataclysm and the nature of Adolla Bursts, as well as the mysteries behind human combustion.