This is a detective adventure game set in Las Vegas, where you track a serial killer, first by the baseball hat left on one victim, and then the bloodied doll that appears on the title screen on the second one. It was originally for the PC-88, and was ported to the PC-98 several years after that release. It contains a pretty responsive and detailed command list, which includes a "JOKER" ability you can use as a kind of bypass when you get stuck, although it does have consequences if used too frequently.
Some discussion of the game and a walkthrough (all in Japanese) can be found on this site. Descriptions of this game on other sites mention it is a single floppy disk, and at least the starting parts of the game and load seem to run fine with just the first disk. As the second disk appears to contain a bunch of related graphics, though, I included it here.