"Holmes Agency" is a private detective office known as the "Big-Eating" Detective Office. Seiya Takano, who is known for have a huge appetite, gets assigned to this office as the new leader. Ryousuke Noda and Kyouko Izumi, both also having a big appetite work under Seiya. Murder, robbery, and kidnapping—many incidents occur around them. And the three solve each of the many cases in a most surprising way—their appetite results in marvelous speculations! They eat at the murder scene. They eat on the track. They even eat dog food! They keep on eating and eating, not even listening to the witness. Everywhere they go, they eat and eat and eat! And every time after finishing, the criminal appears. KUITAN is the words "Big-Eating" and Detective combined together. "Real Gourmet" plus "Real Mystery." The big-eating detectives are on the run, solving cases from their deep knowledge about food.