Sakuya Otsuki, an immortal high school detective who somehow revives no matter how many times he is killed. He was killed by a criminal because... more>> of his innate humor, and while being seen by his excellent assistant Lilithea with cold eyes, he challenges a number of difficult cases based on the clues he brought back from the bottom of his death! <<less

Prequel to the first song in the Vocaloid series, “,” and follows the events between the schoolgirl detective who loves mystery novels, Hanamoto Hibari, and the extremely sadistic mystery novel writer, Kudou Renma.... more>>

As the high school is busy with preparations for the Culture Festival, a female student is found on the roof, collapsed and bleeding.
Written in blood is a single “X.” Is this an accident? Or a case? Hibari sets out to uncover the truth. <<less