Double from the Lunar Dam

The backstory of the detective-astrologer Kiyoshi Mitarai, the main character of the puzzle novels «Tokyo Zodiac» and «The House of Crooked Walls». 
 
Tokyo, 1978.
 
A certain man woke up on a bench in a completely unfamiliar place and gradually realized that he... remembered nothing about his past life and had no idea who he was. Moreover, he discovered that instead of his face, he saw something like a crimson melon in the mirrors. In this hopeless situation, a girl named Ryoko came to his aid, they fell in love with each other, and settled down together. The unknown man took the name Keisuke Ishikawa. Not seeing any other way to find out at least something about himself, he turned to the eccentric astrologer Kiyoshi Mitarai, forming a friendly relationship with him. However, it was not the stars that helped, but rather chance: Keisuke found the first key to the mystery. In Ryoko's belongings. Using this key, he was hit by a whole cascade of shocking discoveries. And only Mitarai, possessing abilities that Keisuke never even imagined, could make sense of them…
 
The book is presented in a clutch book format.