Zukkoke sannin gumi-kaito x monogatari

Midori is a pretty place on one of the many tiny islands in this part of Japan. Over the past few weeks, messages signed by a mysterious ‘Phantom X’ have been received in many of the local towns, threatening an imminent series of burglaries. The anonymous message that arrives in Midori states that the village is shortly to be robbed of its most treasured possession.