A Buddhist "houshi," or low-ranking, itinerant monk, Miroku traveled the countryside performing services such as exorcisms and youkai exterminations to earn his living. He suffers from a hereditary curse originally inflicted upon his grandfather Miyatsu (also a Buddhist monk) by Naraku, who exploited Miyatsu's weakness for attractive women by taking the shape of one, and reflected one of Miyatsu's ofuda back to pierce the palm of his right hand (it appears to be his left hand in the English language manga where right and left are reversed). The hole in his hand became a kazana (air void or "wind tunnel") which sucks in anything not nailed down, regardless of mass.
Miroku uses the kazana as a powerful weapon against youkai, but as he grows older, the kazana grows inevitably larger, and if the curse is not broken by Naraku's death, it will grow too large to control and consume Miroku himself—the same fate his grandfather and his father have already met. Probably as a result of this, Miroku takes a hedonistic approach to life which is uncharacteristic of a proper monk; he is a talented con artist who does not hesitate to invent fictitious supernatural menaces which he can then offer to combat in return for food and shelter, and like his grandfather he has a distinct weakness for pretty women. He makes a point of asking every attractive woman he meets if she will bear his child, claiming that he wants to be sure of an heir to continue his pursuit of Naraku if he dies, and his hands have a seemingly uncontrollable habit of wandering—something which often gets him soundly thumped by Sango, the favorite subject of his groping; however, in spite of his less-than-saintly behavior, Miroku proves to have a core of deep spirituality and, as a result, impressive spiritual powers. ("Miroku" is Japanese for Maitreya.)