Adapted from the author's 2019 oneshot.

[Original Manhua](https://ac.qq.com/Comic/ComicInfo/id/652781)

One-shot published in Harta 107.

A series of mahjong-themed murder mysteries featuring a part-time high-school detective. Included Stories: \- The Chuuren Poutou Murder Case (九蓮宝燈殺人事件) \- The Daisangen Murder Case (大三元殺人事件) \- The Daisuushii Murder Case (大四喜殺人事件) \- The Kokushi Musou Murder Case (国士無双殺人事件) \- Noumen Keibu Satsujin Jiken (能面警部殺人事件)

Sophia, the daughter of a marquess, has been strictly raised from childhood to believe that “a noble lady should never show her emotions." As a result, Sophia always has a blank expression on her face, which causes her to be shunned by other people at school. One day, Sophia meets a foreign student named Felix. He notices Sophia's true feelings hidden behind her expressionless face, and he becomes her confidant. As time goes by, Sophia wishes to express her gratitude to Felix and her special feelings for him… The two of them become closer as the young woman known as “The Iron Mask” opens her heart to a boy for the first time, and her world begins to shine with vivid colors. (Source: Comic Room, translated)

Anthology of short stories based on the Digital Devil Saga: Avatar Tuner 2 video game.