スピカに牢屋に閉じ込められたディアナ。
訳も分からぬまま牢屋を探ると…ディアナの日記を発見。
しかも、そこには衝撃の真実が書かれていた！
一方、ディアナに会いにディアフェル家にやってきたシリウスは、ディアナがいないことに異変を感じ…？
Diana is locked in a prison by Spica. Not understanding why she was trapped there, she searches her cell and finds Diana's diary. What's more, there was a shocking truth written in it! Meanwhile, Sirius, who came to the Diafell household to see Diana, feels something is off when Diana is not there.
