Giman No Satsui (Kadokawa Bunko)

[Machine Translation] The head of the Yulu family, a wealthy local family, died suddenly at the age of 64. His eldest daughter and grandson died at a Buddhist memorial service held at the mansion with only relatives present. A piece of chocolate silver paper with arsenic on it was found in the pocket of the eldest daughter-in-law's lawyer. The former lawyer, who confessed and was sentenced to life imprisonment, exchanged correspondence with those involved in the case. I am not the murderer. In the letters, a guessing game unfolds over the true culprit of the "poisoned chocolate. Eventually, the truth takes an unexpected turn.

地方の資産家・楡家の当主が64歳で急逝。屋敷で行われた身内しかいない法要で、長女と孫が死亡。長女の婿養子である弁護士のポケットからヒ素の付いたチョコレートの銀紙が発見された。自白して無期懲役となった元弁護士は、事件関係者と往復書簡を交わすことに。「僕は犯人ではありません」。書簡の中で繰り広げられる「毒入りチョコレート」の真犯人をめぐる推理合戦。やがて真相が思わぬ方向へ―。