The Detective Boys trailing Kogoro expecting a glamorous case instead watch him botch a stakeout, complain about bills, and accidentally stumble into the actual mystery. It's the show knowing its own formula well enough to laugh at it. You get the warmth of the core cast in miniature, no stakes, just the pleasure of watching kids discover their hero is basically a tired guy who happens to be right sometimes.
The Detective Boys have a school assignment: research any profession that interests them. They choose to follow Kogoro Mouri, the famous private detective, hoping to catch him in action and document what real detective work looks like. What starts as a straightforward day of observation quickly spirals into something far more complicated when a case lands on Kogoro's desk, and the kids find themselves caught up in genuine danger rather than the safe, controlled scenario they expected. As they trail their target through the investigation, the Detective Boys discover that shadowing a real detective is nothing like the glamorous versions they'd imagined. They're forced to think on their feet, stay out of trouble, and figure out how to be useful without getting in the way. Between dodging actual criminals and trying to gather material for their assignment, the group learns hard lessons about courage, teamwork, and what it really means to pursue the truth. It's a fun romp through a day that proves far more eventful than anyone anticipated.