孤島パズル

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...

月光ゲーム Yの悲劇'88

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...

人格転移の殺人

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...?

螢

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.

鴉

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...

『瑠璃城』殺人事件

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.

『ギロチン城』殺人事件

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...

迷路館の殺人

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.

This incident became fairly known afterwards and one year later a literary reconstruction published by Kitansha Novels arrives at Shimada's. It was written under the pen name Shishiya Kadomi, who claims to have been involved in the case, which Shimada acknowledges before he delves into the book...

笑わない数学者

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...

翼ある闇 メルカトル鮎最後の事件

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?