In the wake of their first home burning down, Nasa and Tsukasa Yuzaki are seeking temporary shelter at the Arisugawas' bathhouse. Though they have only been married for a short time, their relationship has only become sweeter by the day. Nasa is determined to spend as much time with his wife as possible, basking in the happiness of their marriage. The newlyweds find new ways to explore their relationship. From adopting a cat, going to an amusement park, and even watching an impromptu romantic comedy featuring Nasa's former teacher, every day is a new experience. But while Tsukasa continues to meet the people in Nasa's life, Nasa has yet to meet more of Tsukasa's family. Though they appear to be the picture-perfect couple to everyone around them, Nasa begins to wonder if he will ever learn more about his wife's mysterious past.

The OVA will be focus on when Kujaku Nijou first entering group, which occurs one year before the main anime begins.

Lily Bridge, a young journalist, arrives at Arkham City, hoping to find a big scoop. However, with all the strange things occuring around the city, only the exceptional findings are news-worthy, such as the mysterious mecha known as Demonbane. However, upon finding a small piece of machinery that seemed to be connected with the Hadou Combine, Lily is determined to find the truth. Little does she know, she enters into a dark world, involving herself with Demonbane and the powerful forces that control the city.

Far to the north of the world lies Hell's Gate, a portal formerly used by the Demon Lord to invade the human realm. Thanks to the legendary hero Shion Bladearts, wielder of Excalibur, and his loyal band of companions, the Gate was sealed off and the demonic threat was vanquished. Unfortunately, the seal was incomplete and has begun to weaken, allowing the demons to once again begin their attack. Worried about the safety of his village, selfish and perverted farmer Touka Scott dig pitfalls to defend against the demons. But fear not, for Shion is on his way to reseal Hell's Gate and save humanity! Or at least he was, because the legendary hero is dead, having fallen into one of the pitfalls Touka dug. Luckily, dealing with the dead is the specialty of necromancer Anri Haynesworth. While she can't revive him, Anri can at least salvage their quest by forcing Touka's soul into Shion's rotting body and dragging him along to Hell's Gate in Shion's place. Not wanting to be left behind, Touka's childhood friend Yuna Yunis tags along. Together, the three of them set out as what just might be the most unsuitable party to ever try to save the world!