"I'll show you a doll."
Hiryuu Souichi moves into the mansion his father left behind after his suicide. The several mannequins standing around there count to the lesser mysteries Souchi encounters in his new environment. Strange sounds at night, threatening letters and the staring gazes from the neighbourhood and eventually a murder incident drive Souchi into calling Shimada Kiyoshi, an old friend of his to make sense of the strange happenings that begin to entangle him.
After the ominous murder incident on Kazune Island, Kisaragi Uyuu suffers from post-traumatic memory loss. To get those memories back he continuously finds himself setting temples and shrines on fire. It turns out later that in each remains of those a corpse is found. On top of that Uyuu receives a letter asking what he intends to burn next. Might Uyuu also be a murderer?
To celebrate the 20th anniversary of their idol Mamiya Kazune, a group of people in their forties gather on Kazune Island where they once spend a year together worshipping her. Looking back on their young days they are accompanied by Kisaragi Uyuu and his assistant Maina Touri, who are supposed to interview them and write an article about their reunion. Eventually a decapitated corpse turns up... on a snowy morning in August.
Invited by their club's first female member Arima Maria, Egami and Arisu go on holiday on her uncle's solitary island resort. Her grandfather, from whom her uncle inherited the island, loved puzzles and also created one before his death, which lets you find his heritage in the form of diamonds once you solve it. While the students ponder on the meaning of the numerous Moai statues scattered over the whole island, 2 guests are found murdered in a locked room and the 2-way radio, the only way to inform the mainland, has been smashed up...
The members from Eito University's Mystery Club decide to go camping during their summer holidays and meet other students with the same idea on their way. Unfortunately the volcano next to the camping area suddenly starts to erupt after 200 years and due to landslides the students become unable to leave the mountain. The tragic situation gets even more ominous when people start to vanish or are found murdered...
A sudden earthquake forces 6 people in a fast food restaurant to take refuge in what seems like a shelter when the restaurant's collapse is nearing. This place however turns out to be a personality switching facility and when they wake up they are situated in an isolated locked up space, with their personalities in swapped bodies, which begin to get murdered soon. Whose personality has murderous intents and what is the motive...?
Six members of an occult spot exploration circle plan on staying in the Firefly Mansion located in the thicket of Kyouto's mountain ranges. One of the circle's prospering old boys bought this mansion known for becoming a crime scene ten years ago when a famous composer, the former owner of the mansion, murdered his six performing musicians in one night. What was supposed to be a mere test of courage and an otherwise relaxed camping among the circle members quickly turns into another murder incident.
After his younger brother Abel returns from a small mountain village not even mentioned on any map and getting murdered shortly afterwards, Kain finds and sneaks into this village to find out the truth behind his brother's life he had there, the reason for his sudden return and the identity of his murderer. His investigations unfold a tale of envy, hatred and hypocrisy...
1989, Japan: A corpse in a locked library. 1243, France: 6 knights suddenly vanishing from a castle. 1918, Battle of Verdun: 4 corpses vanishing from the front. And endless cycle of impossible crime situations and the predestined demise of 2 lovers.
Self-proclaimed detective Makube Nako finds a doll disposed on 'doll mound' that writes the message "Help" with a photo attached, that shows a girl standing in front of a guillotine. This indirect client leads Nako and his friend Yorishina Yuuki to the legendary Guillotine Castle, a place that stores numerous execution tools and is equipped with an excessive security system. One year ago, the castle's lord was found decapitated in a locked room situation with a decapitated Russian doll beside him. After Nako and his companion arrive, Guillotine Castle welcomes them with another locked room murder...
Prominent mystery writer Miyagaki Youtarou invites his 4 disciples, a literary critic, an editor and his wife and mystery maniac Shimada Kiyoshi to his underground labyrinth mansion. However he is found dead when they arrive and a tape tells his disciples of his wish to improve their skills under the condition of being locked into this closed circle situation and write themselves into their works using his mansion as location. Their works are to be evaluated by the critic and the editor and the winner is going to inherit Miyagaki's entire fortune. The authors begin to write their individual stories and it does not take long until murders happen according to those scripts.
Saikawa and Moe are invited to legendary mathematician Tennouji Shouzou's Christmas party in his mansion Mitsuboshikan. While the guests are in the mansion's planetarium, the huge Orion statue in front of the mansion vanishes and the professor challenges his guests to solve this mystery. When the statue appears again later, the corpse of a guest who was supposed to have been in her room is found in front of it, while another corpse turns up in her room...
When the detective Kisarazu Yuuya and his companion and mystery writer Kouzuki Sanetomo arrive at the medieval-ish mansion Souajou, Kisarazu's client has already been killed, just as this client's son, with their heads being cut off and swapped with one body and head found in a locked room. For what sake do the serial murders in the Imakagami family continue? Why all the incomprehensible staging of the murders? And why was Kisarazu hired in the first place?
Various detectives are gathered on Erikajima to investigate Alice Mirror Castle and find the Alice Mirror. A chess board with 10 white figures makes the detectives aware of their situation being strikingly similar to a certain literary masterpiece and the further development unfortunately supports their hunches...
The exorcism of a spirit whose grudge founded a whole family curse calls forth seemingly impossible crimes and forces Nikaidou Ranko to uncover the secrets of the Masamiya family and the fate that is about to befall the three sisters.
The odd-looking 'water wheel mansion' inhabited by a masked host and a lonely young woman... Last year in a stormy night it was haunted by an unfathomable tragedy. Will the nightmare occur this year again? The secret of Fujinuma Issei's posthumous visionary painting and the mysterious disappearance of Shimada Kiyoshi's friend from a locked room guides Shimada to the mansion to uncover the secret truth hidden behind the steadily turning water wheels...
In 1994 a sunspot 30 times as huge as the earth was discovered and by its influence the planet has been in disorder since then. The world is said to meet its demise in 1999. It is in that year, that a certain request for detective Minami Miki drops in. He proceeds to Clock Castle, whose outer wall is furnished with 3 huge clocks which display past, present and future, and whose interior is divided into 3 separate mansions as well. The proprietor's daughter, Kurou Ruka, is said to be Midnight's Key, a crucial being in earth's final moment. She asks Miki to investigate the eerie face staring out of the cellar's wall. Ruka suspects a ghost called Skipman, which rumor has been passed on in the mansion for generations. This Skipman is supposed to be able to rip a hole into time and travel into the past and future. Soon after Miki begins his investigations, a seemingly impossible murder resembling the legend of Skipman ensues...
Assistant professor Kita Hokuto invites his friend Saikawa Souhei and consequently Nishinosono Moe to the cyrogenic research facility he is working at. In the cyrogenic laboratory a murder happens. Despite all surveillance during the experiment, two students are found dead in a complete locked room situation. How did the culprit enter the room and how did he escape when even the two victims could not have entered the room in the first place?
Takasuka Katsushi, a young man lacking certain memories and Itsukinomiya Mei, a girl that closed her heart, meet on a cram school's rooftop. He feels gravitated towards crime scenes and takes photos of those while she seems like a living corpse wearing huge disconnected headphones. They soon wind up in solving various mysteries happening among the students at the cram school.
After being accused of murdering her parents at the age of 14 and considered as certifiably insane due to her multiple personality disorder, computer scientist and overall genius Magata Shiki retired from the world and lives in her own little locked room in the Magata research facility on an isolated island. 2 doors separate her from the rest of the facility. The inner one can only be opened with her admission while the outer door can only be opened by the other facility members and she has not left her space for 15 years. When engineering assistant professor Saikawa Souhei and his student and his former professor's daughter Nishinosono Moe request a meeting with professor Magata in this threefold locked room, a corpse wearing a wedding dress advances out of the room and what is left in there is a computer displaying the incomprehensible message 'all becomes F'...
Nikaidou Reito and Ranko's friend Kurebayashi Hideki and his family are threatened by a mysterious mummy-like man who announces to murder the whole family out of revenge on Hideki's uncle, Kurebayashi Yoshihiko. Reito and Ranko also wind up in the serial murders and Ranko gets to work on her first larger case.
Mizuno Satoru, temporary deputy supervisor of a travel agency, and Minami Yukari, one of this agency's employees, get caught up as suspects in various murder cases in Karuizawa's area by coincidence and end up forced to make sense of these peculiar murders to prove their own innocence.
On their investigation of Shizunai Mizuki's birthplace, attorney Kawajima Koujirou and his friend Naka Kunihiko, with the only clues being the diary and a letter from her uncle, stumble upon a murder and the mystery of a resurrecting mummy from 20 years ago. Following their investigations, another murder occurs...
Tsunojima, Aoyashiki's burnt down remains and a decagon-shaped guesthouse. The latter is used by seven students from a university's mystery club and as someone would naturally expect considering this setting, serial murders start happening on this otherwise uninhabited island with no one willing to confess the crimes. Two other students who did not visit the island with their fellow students receive mysterious letters from Nakamura Seji, the proprietor of former Aoyashiki and the whole island, who supposedly died in the incident in the mansion half a year ago. They find out that those letters were also sent to their meanwhile absent fellow students and they begin investigating the incident of Tsunojima's past...
Having his childhood friend killed by one of the bizarre serial murders unsettling suburbia recently, Amane Sanshirou attempts suicide. However synesthete and detective Otomiya Miya prevents this and they end up investigating the serial murders together.
Science magazine journalist Sumisaki Yutori visits the deep-sea experiment facility 'Bubble' for her research. She learns about the death of one of the facility's permanently based inhabitants which was handled as suicide due to a certain locked room circumstance. However during Yutori's stay the mysterious fatalities continue and it becomes questionable if these events can still be seen as suicides or accidents...
1987 a murder happened in the property of the Mallarmé-fascinated retired professor Zuimon Ryuuhshirou. At that time among others the great detective Mizuki Masaomi and his assistant Ayui Ikusuke were guests of Zuimon. Of course Mizuki solved the case brilliantly and Ayui created a new novel in his series depiciting Mizukis astonishing achievements. However this work was never collected as a tankoubon volume and remained unfinished in magazine form...
Due to the sudden information on the arrest of phantom thief Mubou, the great detective Akitsu Shouichirou and his assistant Komura Nozomi head to Natsuhara Hotel, where Mubou is held captive, to gather with the other 2 well-known members of the '3 great detectives'. Being indwelled by Akarumi, the hitodenashi of earthquakes and dreams, the Hotel is also called Mukyou Hotel due to the week of dreams happening once a year when the hotel itself picks out a certain number of customers and sends them into its dream realm to experience the unusual free of charge. To be recognised as Akitsu's offical assistant, Nozomi has to prove his abilities as this year's 'hotel detective' during the week of dreams and it doesn't take long until the first corpse turns up...
In a world where humans are coexisting with mysterious creatures called 'hitodenashi' the great detective Akitsu Shoutarou, who was deprived of his face by the phantom thief Mubou, the hitodenashi of humans and souls, recruits the 15 year-old Komura Nozomi, who was sold by his parents at the age of 5, as his assistant. At the same time Mubou announces his next target: The tongue of Enoki Sari, one of the daughters from a family well-known for their railroad company. Akitsu and Nozomi are hired as guards for Sari and eventually Nozomi instead of the great detective finds himself investigating the serial murders happening within the Enoki family...
Teshigawara Jun, a famous blind scientist and his female assistant Morishima Yuka, three other scientists and one doctor plan on spending time gathering data in a concreted shelter located in one of the pillars maintaining the world's biggest oversea suspension bridge. One day after they arrived and settled in an earthquake happens which causes the security system to lock up the whole complex. On top of that the communication system is found destroyed and the six find themselves in a complete locked-room situation. And of course, murder after murder happens until only Teshigawara and Morishima are left...