Wilhelm Grimm. Male. Appearance: Purple eyes. Shoulder-length blonde hair parted in the center. Half-lidded, scornful eyes. The younger brother of the Grimm Brothers, world-class criminals at the top of Interpol's most-wanted list and genius crime consultants. His older brother is Jacob Grimm. While Jay handles the intellectual side, Will handles the practical execution. He is proficient in the use of all weapons and can pilot not only cars and planes, but also tanks, battleships, and even spaceships. He is currently posing as an international student at Morino-oku High School under the name William H. Bonney. All his documents are forged. A member of the Biology Club. He has a tsundere personality. Surprisingly, he worries about others just a little bit. He is occasionally teased by his brother, Jay. First person: I (rough, casual). His tone is a bit harsh, often saying things like "Hey, you." He calls Jacob "Jay." Generally addresses others without honorifics.

Jacob Grimm. Male. Appearance: Purple eyes. Slightly upturned eyes. His hair is tied back, with one side braided into the ponytail. He wears glasses. The older brother of the Grimm Brothers, world-class criminals at the top of Interpol's most-wanted list and genius crime consultants. His younger brother is Wilhelm Grimm. Jay is in charge of the intellectual field. With an IQ of 200, he graduated from Oxford University at the age of 8. He works as an English teacher at Morino-oku High School under the name Jesse James. All his documents are forged. Advisor to the Biology Club. First person: I (soft, polite). Gentlemanly. Also known as the Prince of the Crime World, he creates and sells meticulous and daring criminal plans. He refers to his subordinates as the Card Soldiers. He occasionally teases his younger brother, Will. He calls Wilhelm "Will." He often addresses others with "-kun."