High school student Hajime Kinda'ichi is unmotivated, lazy, and a little lecherous, much to the exasperation of childhood friend Miyuki Nanase. However, only a few people see his great intelligence and deductive prowess by his 180 IQ, possibly inherited from his grandfather, private detective Kosuke Kindaichi (a fictional character written by Seishi Yokomizo; called the "Japanese Columbo" by some; However, the creators of this series did not get permission from Yokomizo's family, and they eventually complained when the series became popular. It appears to have been settled without a lawsuit, and Kosuke as Hajime's grandfather is not explicitly mentioned in the later episodes).
His catchphrases are, "In the name of my grandfather...", when he commits himself to solving a murder mystery, and, "This mystery is solved!", indicating to readers that they are now in possession of all facts needed to correctly deduce the killer's identity and methods. He is also an accomplished sleight of hand artist. He is billed to have been quite unpopular with girls, but his kindness has in fact captured the hearts of many female characters throughout the story, such as Miyuki Nanase, Reika Hayame, and Sakura Izumi. Despite his clumsiness and myriad other flaws, he is a loyal friend and a first-rate detective.