Teen detective Hajime Kindaichi takes part in a game show where the contestants must find a hidden treasure on an island, but a killer named the Alchemist complicates things. One of the other contestants is Saburomaru Yutaka. Hajime Kindaichi, the grandson of Seishi Yokomizo’s detective Kosuke Kindaichi, is already in the CU through an encounter with Columbo’s nephew. Saburomaru Yutaka is from another manga by this story's creative team of Seimaru Amagi and Fumiya Satō, Detective School Q.
This crossover is one of hundreds covered in my book Crossovers Expanded: A Secret Chronology of the World Volume 3, which will be published by Meteor House! All three volumes are AUTHORIZED companions to Win Scott Eckert's Crossovers: A Secret Chronology of the World Volumes 1 and 2!