The story details the exploits of Hitomi and Mori, two best friends who owe the Japanese government 100 million yen for derailing a train during a childhood prank. In a series of increasingly wacky episodes, this eccentric-yet-resourceful pair test their friendship, their personal mettle, and the limitations of Japanese society in their quest to acquire a whole lotta money.

Loan Wolf was partially published in English as an ebook by ComicsOne in 2000.