Yasuda Ippei (Shonozaki Ken) is the son of Yasuda Seijiro (Osugi Ren), the head of Yasuda Group, Japan's biggest business conglomerate. Although he is the son of a distinguished family, he has absolutely no disagreeable areas and is liked by everyone.

His academic achievements are exceptional. He completed his entire high school programme in 2 years and qualified for Tokyo University's Faculty of Law without studying for the exams. In order to establish his own concept of justice, Yasuda leaves his position as the heir to the Yasuda Group to attend the police academy. He becomes a detective at Kyobashi Police Precinct and bravely faces great evil.