In a world where a mysterious illness, Occupational Disease, is known to drive people who are too skilled at their jobs insane, government officials dubbed "Shigoto Osame" have been appointed to "treat" those affected.

High school student Shimizu Shizuku lives with one such Shigoto Osame, Kuujo, who just so happens to be the one who "treated" his own parents. While he absolutely loathes Kuujo for taking his parents from him, once various mysterious incidents begin to happen around them Shimizu has no choice but to count on the other man for help.