Mizuno Eita

The story is set in the modern world, but there exist doors that can take people to the "other side," where strange urban legends and internet stories prove to be true. College student Sorawo Kamikoshi finds herself exploring one of these doors, and almost dies on the other side, when she is rescued by another girl named Toriko Nishina. Toriko is a mysterious girl, but very skilled with a gun, and she seems to be searching for someone else on the other side. Together, both girls start to explore these doors to the other side.

The story takes place in the city of Tokui, which has a legend of two monsters. Yūko Tengai transfers to the town's high school out of season in order to look for clues to clear her older brother of suspicion in a 10-year-old murder case. She teams up with her classmate Masaki Maki, who was in a coma for eight years, and her brother, who uses a robot to communicate to them from his zashikirō (Edo period-style room for confining criminals). But Yūko has a true form…

The time for logical debate and magical feints has come to an end; the revelation of the truth about Beatrice the Golden Witch is at hand. To facilitate this, game master Bernkastel has chosen Will Wright the Mage-Hunter to step onto her board and answer a single question: Who killed Beatrice? Joining him in the game is Lion Ushiromiya, Krauss's firstborn and heir, whose role is a mystery in its own right. Will's line of questioning draws together the stray strands from all the previous games, twisting them into a thread of truth, revisiting Kinzou's first encounter with the young Beatrice and working through the legends that have since sprung up around her... \[Yen Press]

This is a spin off story that occurs some years before Spiral. The main character is Imari, who is in love with the kid who wants to be a detective, and that he quits school running after Kiyotaka, and it seems he's dating a murderer without knowing it…? But how is it all connected to the blade children?

World-class detective Kiyotaka Narumi’s last words prior to his sudden disappearance continue to haunt his younger brother, Ayumu. The cheeky 10th-grader becomes equally embroiled in the mystery of the doomed “Blade Children” when he is mistakenly named the prime suspect in a murder at his school. Led by Ayumu’s sister-in-law, Kiyotaka’s wife and fellow detective, Madoka, the investigation into the murder gives Ayumu a chance to clear his name. But in doing so, he not only uncovers ties to the Blade Children but also more questions than answers about who and what they are.