Mystery in Nagano: The Torada and Ryuubi Families' Secret

In an intriguing turn of events, the famous detective duo, along with friends, find themselves entangled in a mystery involving two of Nagano's most prestigious families, the Torada and the Ryuubi. Amidst the scenic backdrop of Nagano, they encounter Heiji Hattori and Kazuha Toyama, who are there on a separate request. The plot thickens with the involvement of Inspector Yamato Kansuke, making this a case that promises to test their deductive skills to the limit.