Crooked businessmen and civil servants got you down? Call the undertaker of the tax world, the Tax Reaper. Jae-Hyeon Sin has a gift that lets him see the amount of illegally withheld taxes as a number floating above people’s heads. But when he uses this ability to whistleblow on someone in his own company, he gets the axe. Branded a traitor in the business world, he decides to become a government employee and catch all the dirty white-collar criminals that profit through tax loopholes. Who’s neck will the Tax Reaper’s righteous blade strike next?

주인공 '신재현'은, 다니던 기업의 비리를 고발했다는 이유로 직장을 잃고 배신자라 불리게 된다. 이에 굴하지 않고 세무직 공무원 합격을 목표로 했지만, 그마저도 어려운 집안 환경 앞에 흔들린다. 좌절하던 그에게 '은인'이 손을 내밀고, 훗날 국세청의 망나니가 될 자는 비로소 칼을 손에 쥔다. "탈세자라면 어디의 누구든, 전부 잡아내겠습니다."